Gantry machining center automatic tool selection and change:
Gantry machining center is a CNC machine tool equipped with a tool magazine, which can automatically change tools and process workpieces in multiple steps. After the workpiece is clamped once, the CNC system can control the machine tool to automatically select and change tools for different processes, automatically change the spindle speed, feed rate, and the relative motion trajectory of the tool to the workpiece, and other auxiliary functions, to complete the processing of multiple steps on several faces of the workpiece in turn.
Due to the concentration of processes and automatic tool changing, the machining center reduces the time for workpiece clamping, measurement, and machine tool adjustment, making the cutting time of the machine tool reach about 80% of the machine tool operating time (normal machine tools are only 15-20%); it also reduces the turnover, handling, and storage time between processes, shortening the production cycle and achieving significant economic benefits. The machining center is suitable for medium and small batch production with complex shapes, high precision requirements, and frequent product changes.
The machining center was first developed by the American Kearney & Trecker company in 1958. It is based on the CNC gantry boring and milling machine and adds an automatic tool changing device, which enables centralized processing of various processes such as milling, drilling, boring, tapping, etc. after the workpiece is clamped once.
Since the 1970s, machining centers have developed rapidly, and there have been machining centers with interchangeable spindle boxes, which have multiple multi-axis spindle boxes with automatic tool changes that can simultaneously process multiple holes in the workpiece.
This form of centralized processing with multiple processes has also expanded to other types of CNC machine tools, such as CNC turning centers, which are equipped with multiple automatic tool changing devices on CNC lathes, can control three or more coordinates, and in addition to turning, the spindle can stop or index, and the tool rotates to perform milling, drilling, tapping, and threading processes, suitable for processing complex rotating parts.
Machining centers are classified into vertical and horizontal types according to the arrangement of the spindle. Horizontal machining centers generally have indexing rotary tables or CNC rotary tables to process various side surfaces of the workpiece; they can also perform coordinated motion of multiple coordinates to process complex spatial surfaces. Vertical machining centers generally do not have rotary tables and are only used for top surface processing. In addition, there are composite machining centers with both vertical and horizontal spindles, and vertical-horizontal adjustable machining centers where the spindle can be adjusted to a horizontal or vertical axis, allowing for processing of five surfaces of the workpiece. The automatic tool changing device of the machining center consists of a tool magazine for storing tools and a tool changing mechanism. There are many types of tool magazines, with the most common being disc and chain types. Chain tool magazines have a larger tool storage capacity.
The tool changing mechanism exchanges tools between the machine tool spindle and the tool magazine, with the most common being a robot arm; there are also tool changing devices without robot arms, where the spindle exchanges tools directly with the tool magazine, known as armless tool changing devices. In order to further reduce non-cutting time, some machining centers are equipped with two automatic pallets for exchanging workpieces. One pallet holds the workpiece for processing on the worktable, while the other pallet loads and unloads the workpiece outside the worktable. After the machine tool completes the processing cycle, it automatically exchanges the pallets, aligning the loading and unloading of workpieces with the cutting process. For more information about gantry machining centers, please visit: http://www.yxskkj.com.cn
