Causes and solutions of tool collision in machining center

1. Problems with the machine origin and coordinate system will cause tool collision

The first thing we should think of is the setting of the origin of the machine tool coordinate system. This machine tool in incremental configuration is *obviously, when the machine is turned on, the machine origin is not set. At this time, running the program will cause the machine tool to hit the tool accidentally, because the system I don't know the exact position of the machine tool, and the machine origin is incorrect. For machine tools that use incremental position encoders, the zero-return installation fast position is incorrect each time the zero-return position is incorrect. Therefore, the installation fast position needs to be adjusted. If the machine origin is set incorrectly, tool collision is likely to occur when running the program.

　　The second is the setting of the workpiece coordinate system. Before the processing operation, the zero point of the workpiece coordinate system (G54-G59) is set incorrectly or the coordinate system is incorrect. At this time, the processing will easily cause the tool to hit or the size of the processed workpiece is incorrect.

　　 2. The parameter is set incorrectly or has been changed by mistake, the data unit is disordered during processing, and the workpiece is prone to incorrect size or tool collision

　　 (1) The machine tool follows the program. If there is a problem with the given program itself, it will definitely hit the tool. Part of the G code of FANUC is modal. If the G code formulated in the previous processing program or block of the program is not cancelled at the end of the block, it will continue to be valid in the next program or block, which may cause the machine to malfunction. Or cause a knife hit.

　　(2) The setting parameters are wrong or changed by mistake

　　NO 000#2 INI setting error 0: Metric unit 1: Imperial unit.

　　NO 3401#0 DPI Address word using decimal point, meaning of decimal point. When the decimal point is omitted,

　　0: setting * small setting unit

　　1: Regard as mm inch, the angle is 1°.

　　 3. Misoperation during processing

　　 (1) During the normal processing of the program, the program is stopped due to a misoperation. If the wrong operator presses "RESET" to reset the program immediately, it will start the cycle immediately, at this time, it is prone to tool collision.

　　 Reason: The default value of operation and the set value of the program have changed. Press: RESET: Reset will reset the CNC system to the initial state, clear the prediction program information stored in DRAM, and may also change the tool movement instruction.

　　 G90 absolute command: run according to the commanded coordinate value.

　　 G91 incremental value command is executed according to the commanded movement distance.

　　 Avoidance method: If the program stops running due to misoperation during the automatic running of the program, modify it to edit mode at this time, press RESET to reset the program, and re-run the program, even if it is converted from MDI to MEM, be sure to check each modal code. (G M S F T, etc.) After confirming that the disease is correct, start the automatic cycle, otherwise it may cause serious consequences.

　　(2) There is also an error in the setting of the tool compensation value.

　　 If the tool compensation value is set incorrectly, it will also cause tool collision. Regularly check whether the tool compensation value is correct to avoid the occurrence of tool collision accidents.

　　 In fact, there are many reasons for the collision of the CNC machining center, but the possibility of failure caused by the system hardware is very small. As long as management is strengthened, misoperation is reduced, tool compensation value and workpiece coordinate system settings are regularly checked, the origin is confirmed before machining, and all aspects of inspection are done, most of the tool collision accidents can actually be avoided.