Numerical control processing has good flexibility and high degree of automation. It is especially suitable for processing curved and curved parts with complex contours, as well as complex boxes and prismatic parts with a large number of holes and grooves. In the case of multi-variety and small batch production, use CNC machine tools Processing can obtain higher economic benefits.

The processing of large-scale CNC machining process problems is basically the same as that of ordinary machining, but has its characteristics. Therefore, when designing the CNC machining process of parts, it is necessary to follow the flexibility of CNC machining and high degree of automation. It is especially suitable for processing curves and curved parts with complex contours, as well as complex boxes and prismatic parts with a large number of holes and grooves. , In the case of multi-variety, small batch production, the use of CNC machine tools can obtain higher economic benefits.

The tool setting point and tool change point of the large-scale CNC machining center are determined. The tool setting point is the starting point of the tool relative to the workpiece during CNC machining. Since the program is also executed from this point, the tool setting point is also called the program starting point or starting point. When programming, you should first consider the selection of the position of the tool setting point. When the machining accuracy is not high, you can directly use some surfaces on the workpiece or the fixture as the tool setting surface; when the machining accuracy is high, the tool setting point should be selected on the design datum or process datum of the part as much as possible, such as hole positioning It is more appropriate to take the axis of the hole as the tool setting point.

The tool setting point must have a certain coordinate relationship with the positioning datum of the workpiece, so that the relationship between the machine tool standard system and the workpiece coordinate system can be determined. The selection of tool setting points should facilitate the calculation of coordinate values and make tool setting convenient. When setting the tool, the tool setting point should coincide with the tool position point. The so-called tool location point refers to the intersection of the tool axis and the bottom surface of the tool for flat-bottomed end mills; for ball end mills, it refers to the center of the ball head; for turning tools, it refers to the tip of the tool; for drills, it refers to the point of drill; Wire electrode cutting machine tool refers to the focus of the wire electrode axis and the part surface. When the tool needs to be changed during the machining process, the tool change point should be specified, and the position of the tool change point should be set according to the principle that the workpiece, fixture and machine tool should not be damaged during tool change.