The CNC machining center is an automatic machine tool with a program control system.
As the manufacturing industry has higher and higher requirements for intelligence and automation, CNC machining centers are developing rapidly in my country, especially in South China and East China. According to statistics, the number of CNC machine tools used for mobile phone shell processing is hundreds of thousands of orders of magnitude each year, and the market is huge!
1. Processing center classification
Machining centers are usually divided into vertical machining centers, horizontal machining centers, gantry machining centers, and universal machining centers according to the spatial state of the spindle. The space of the spindle of the machining center in the vertical state is called the vertical machining center, and the space of the spindle in the horizontal state is called the horizontal machining center.
Vertical machining center: the structure is mostly fixed column type, the worktable is rectangular, suitable for the processing of plates, covers, and plate parts. Vertical machining centers usually have three linear motion coordinates, XYZ axis and the fourth axis A can be installed on the worktable.
The vertical machining center is easy to clamp, easy to operate, easy to observe the machining process, and easy to debug. However, due to the influence of the height of the column and the tool change mechanism, parts that are too high cannot be processed. The vertical machining center has a simple structure, a small area and a low price.
Horizontal machining center: usually use movable column, the headstock is between the two columns and moves up and down along the guide rail. Horizontal machining centers usually have three linear motion coordinates, facing the machine, moving left and right as X axis, moving forward and backward as Z axis, and moving up and down as Y axis. The horizontal machining center can also be installed on the table, and the fourth axis is one axis. It can process spiral, cylindrical cam and other parts.
It is inconvenient to observe the debugging program and the pin-cutting test of the horizontal machining center, the processing is inconvenient to monitor, the clamping and measuring of parts are inconvenient, but it is easy to arrange the pin processing. Compared with the vertical machining center, the horizontal machining center has a complicated structure, a large area, and a higher price.
Gantry machining center: Most of its spindles are vertical, equipped with an ATC system, and equipped with replacement spindle head accessories. The system software has many functions and is multi-purpose, suitable for processing large parts.
Universal machining center: The universal machining center is a five-sided machining center with the functions of a vertical machining center and a horizontal machining center. After the workpiece is clamped once, all side and top surface processing except the mounting surface can be completed. Common general-purpose machining centers are: 1) The spindle can be rotated 90 degrees, which can be like a working vertical machining center or a working horizontal machining center. 2) The spindle does not change its direction, and the worktable rotates 90° with the workpiece. Complete five-sided processing.
According to the number and function of the workbench: there are single workbench machining center, double workbench machining center, multi-workbench machining center.
2. The structure of the machining center
Generally speaking, it mainly consists of the following parts.
- (1) Basic components. It is the basic structure of a machining center, which is composed of a bed, a column and a table. It mainly bears the static load of the machining center and the cutting load generated during the machining process, so it must have sufficient rigidity. These large parts can be cast iron or welded steel structures. They are the largest and heaviest parts in the machining center.
- (2) Spindle parts. It consists of a spindle box, a spindle motor, a spindle and a spindle bearing. The spindle's start, stop, speed change and other actions are controlled by the CNC system, and participate in the cutting movement through the tool mounted on the spindle, which is the output component of the cutting power. It is the key component of the machining center, and it determines the machining accuracy and stability of the machining center.
- (3) Numerical control system. The numerical control part of the machining center is composed of numerical control device, PLC, servo drive device and operation panel.
- (4) Automatic tool change system. It is composed of tool magazine, manipulator, drive mechanism, etc. When the tool needs to be replaced, the CNC system issues a command to move the tool from the library into the spindle hole by the cnc machining center manipulator (or through other means). Solve the tasks of automatic storage, selection, transportation and exchange of tools in the processing process
