With the rapid development of numerical control technology and the wide application of CAD/CAM technology, numerical control processing is increasingly dependent on automatic programming of software, and manual programming has gradually taken a secondary position. However, in actual processing, if you combine automatic programming with manual programming, and use the G92 position setting function to cooperate with subprogram calling, you can simplify programming and optimize the program, which is conducive to program modification and repeated calling.
Take the US SABRE-1000 Acramatic 850SX system vertical machining center machine as an example to discuss the coordinate setting (position setting) and subroutine call.
The machine tool coordinate system is a unique coordinate system on the machine tool, which is set by the machine tool manufacturer. The workpiece coordinate system is a coordinate system determined by the programmer based on a certain fixed point on the part drawing as the origin when programming the processing program. The unity between the two coordinate systems is realized by preparing the position setting function of function code G92.
G92 position setting function allows the operator or programmer to assign new coordinate values to the current coordinate axis without the worktable moving. G92 offsets the machine coordinate system to match the coordinate value of the workpiece coordinate system in the NC program.
The origin of the workpiece (the zero point of the NC program) is positioned by the operator during the installation of the workpiece. When compiling the program, programmers can ignore the physical position and installation accuracy of the workpiece on the machine tool, and use the origin offset function of the CNC system to compensate the workpiece clamping error through the workpiece origin offset. The offset value is input to the numerical control device before processing, and the offset value can be automatically added to the workpiece coordinate system during processing, so that the numerical control system can process the workpiece according to the coordinate value of the workpiece determined by the machine tool coordinate system. However, it will be more convenient if G92 is directly programmed into the program instead of inputting the offset value to the numerical control device.
The mold has 6 identical cores. If only automatic programming is used without manual editing, each core needs to be drawn and programmed completely. The workload is large, the program volume is larger, and it is not convenient to check the program.
If you combine manual programming with automatic programming and use CAD/CAM software for automatic programming, you only need to draw a core and generate a program for processing a core. According to the positional relationship between the cores, a simple and clear program can be obtained through G92 setting and subprogram calling. Moreover, if the tool has worn out during the machining process, after changing the tool, you can easily modify the program to continue machining the next core.