Structure and Components of Machining Center
The foundation of a machining center consists of the bed, columns, and worktable, among others. These components primarily bear the static and cutting loads generated during machining. Consequently, they must possess sufficient rigidity. These larger parts can be made of cast iron or steel structures assembled by welding. They represent the largest and heaviest elements in the machining center. AKIRA-SEIKI employs high-grade Meehanite castings for stability after undergoing heat treatment.
The spindle assembly comprises the spindle box, spindle motor, spindle, and spindle bearings. The start, stop, and speed variation of the spindle are all controlled by the CNC system. The cutting tools mounted on the spindle participate in the cutting motion, making the spindle the power output component for cutting operations. It is a critical part of the machining center, determining its processing precision and stability.
The CNC part of the machining center consists of the CNC unit, programmable logic controller (PLC), servo drive devices, and the operator panel.
Automatic Tool Changer System
This system includes the tool magazine, mechanical arm, and driving mechanisms. When a tool change is required, the CNC system issues commands, and the mechanical arm (or other means) retrieves the tool from the magazine and inserts it into the spindle hole. This system addresses the automatic storage, selection, handling, and exchanging of tools between consecutive machining processes after a workpiece is clamped for multiple operations. The tool magazine can have different capacities, ranging from a few to several hundred tool positions. The structure of the tool arm varies depending on the relative position and structure of the tool magazine and spindle, such as single-arm or double-arm configurations. Some machining centers achieve tool changes directly through the movement of the spindle box or tool magazine.
These include lubrication, cooling, chip evacuation, protection, hydraulic, pneumatic, and detection systems, among others. Although these devices do not directly participate in the cutting motion, they play a crucial role in ensuring the machining efficiency, precision, and reliability of the machining center. As such, they are indispensable components of the machining center.
Automatic Pallet Changer (APC) System
Some machining centers use multiple automatic exchange worktables to achieve further unmanned operation or reduce non-machining time. One workpiece is mounted on a worktable for processing, while another worktable can load or unload other parts. When the processing of one workpiece on a worktable is completed, the system automatically exchanges the worktable for processing a new part. This approach reduces auxiliary time and improves machining efficiency. For more CNC knowledge, search for the public account “CNC Programming Teaching” on WeChat to receive free tutorials.