The five axis mold carving and milling machine, with its multi axis collaborative motion capability, has become the core equipment for complex mold processing. Its performance depends on the rigid design of the mechanical structure and the precise coordination of motion control. A deep understanding of the internal logic of these two aspects can help grasp the processing capability and precision characteristics of the equipment.
The design of mechanical structures revolves around "rigid support+flexible motion". The bed and column are made of integral casting or welding structure, and internal stress is eliminated through aging treatment to ensure structural stability during heavy load processing. The workbench system is the foundation for achieving multi axis motion, with the X and Y axes forming a horizontal motion platform. It uses a combination of high-precision ball screws and linear guide rails, with screw pre tightening design to eliminate reverse clearance, and guide rail quenching treatment to improve wear resistance; The Z-axis controls the vertical lifting and lowering of the spindle, which is directly driven by a counterweight or servo motor to ensure smooth up and down movement. The two additional rotation axes (usually A-axis and C-axis) are the key to the five axis function. A-axis enables the worktable to swing around the X-axis, while C-axis enables the worktable to rotate around the Z-axis. Both are driven by high-precision worm gears or harmonic reducers, balancing rotation accuracy and torque output. The spindle unit adopts an electric spindle design, integrating high-speed motors and precision bearings, which can achieve high-speed rotation of tens of thousands of revolutions per minute, meeting the strict requirements of mold processing for surface quality.
The core of motion control principle is the spatiotemporal coupling of multi axis linkage. As the "brain", the numerical control system receives the machining code generated by CAD/CAM, decomposes the 3D mold model into countless tiny spatial coordinate points, and calculates the motion trajectory of each axis through interpolation algorithms. For example, when processing the surface features of a mold, the system calculates the linear displacement of the X, Y, and Z axes and the rotation angles of the A and C axes in real time, so that the tool always maintains the optimal cutting posture with the surface. This linkage control relies on the "feedforward control+feedback compensation" mechanism: the feedforward control judges the motion parameters of each axis according to the trajectory, and adjusts the servo motor output in advance; The position feedback devices such as grating rulers and encoders collect the actual positions of each axis in real time, and the deviation compared with the command values is corrected by PID algorithm to ensure that the motion accuracy is controlled at the micrometer level.
The dynamic matching of each axis is a difficult point in motion control. There are differences in the inertia and response characteristics of different axes. For example, if the motion inertia of a linear axis is greater than that of a rotating axis, the system needs to adjust the acceleration and acceleration of each axis through parameter optimization to avoid trajectory deviation caused by response lag during linkage. For example, during high-speed corner machining, the system automatically reduces the feed rate to synchronize the transition of various axis movements and reduce the impact vibration on machining accuracy. In addition, the coordinate conversion between the rotating axis and the linear axis requires real-time calculation through a kinematic model to convert the spatial posture of the tool into motion commands for each axis, ensuring the accuracy of tool position during complex surface machining.
The rigidity of mechanical structures provides a physical basis for motion accuracy, and the algorithm for motion control achieves precise coordination of multi axis motion. The deep integration of hardware and software enables the five axis mold carving and milling machine to withstand the cutting load of mold processing and complete high-precision processing of complex trajectories, becoming an indispensable technical equipment in modern mold manufacturing.