CNC machining center is a machining tool. It is inevitable that there will be knife collision due to misoperation by different people. If there is a knife collision, how to diagnose the cause of the knife collision? What are the common reasons for the knife collision? The following is the phenomenon of a knife collision report summarized by a maintenance master. Only if you know the cause of the knife collision, in the actual maintenance, you can accurately judge the failure of the knife collision.
One, the machine origin and coordinate system problems can cause tool collision
The first thing we should think of is the setting of the origin of the machine coordinate system. This machine in incremental configuration is *obviously, when the machine is turned on, the origin of the machine is not set. At this time, running the program will cause the machine tool to hit the tool accidentally. I don’t know the exact position of the machine tool, and the machine origin is incorrect. For machine tools using incremental position encoders, if the zero return and fast position are incorrect, the zero return position is incorrect each time. Therefore, the 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 machining operation, the zero point of the workpiece coordinate system (G54-G59) is set incorrectly or the coordinate system is incorrect. At this time, the machining will easily cause the tool to hit or the size of the processed workpiece is incorrect.
2. The parameter setting is wrong or it is changed by mistake, the data unit is disordered during processing, and the workpiece is prone to wrong size or tool collision.
(1) Everyone knows that 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 parameter is 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 and immediately starts the cycle, tool collision is likely to occur at this time.
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 predicted 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.
Summary: There are many reasons for the CNC machining center to cause tool collision, 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 be avoided.