Tool change program and tool change fault detection of CNC machining center
The tool change command of CNC machining center is M06 command. A new tool is called from the tool magazine and installed on the spindle. The lathe returns the old tool on the spindle to the tool magazine. After executing the M06 command, the tool will be automatically installed on the spindle. Machining center M06 is a non modal post action M function. Before the M06 command is executed, the G28 command must be used to make the machine tool return to the reference point, and all compensation must be canceled. This is because there is an incremental position detection element for the Z-axis. In order to ensure the reliability of the spindle quasi stop function during tool change, the machine tool must be returned to the reference point, otherwise the tool change operation may not be completed.
Under normal circumstances, the main reasons for the failure of the tool change function of CNC machining center are: a wrong input or output signal, short circuit, open circuit, position detection failure, tool magazine disorder, tool counter error, and relay damage; Due to the hydraulic and pneumatic systems associated with it, the machinery is stuck, loosened, etc. However, there are some faults that are seldom encountered, especially when the data is ominous and there is no prompt, the fault point is hidden, the alarm information is few, or even there is no alarm, you need to observe and analyze carefully.
In the automatic processing mode, when executing the tool change statement (M06), suddenly jump to the following interpolation statement, and directly process with the original tool without changing the tool. At the same time, the tools in the magazine are still in the preselection process. There is no alarm information. In general, it is common that the tool cannot be changed or the tool change statement cannot be executed. In this example, the tools in the automatic tool library are still in the preselection process, and the original tools are already being used for processing.
In order to ensure personal and equipment safety, the machine must be shut down immediately. To further find out the cause, execute the tool change statement (such as "T2; M06") separately in MDI mode, and the tools can be exchanged. It is thus determined that it is not the problem of the executing agency itself. Whether the system operation is not standardized, the power supply voltage fluctuates greatly or other external interference factors cause the system to be disordered occasionally. Restart the operation, and the fault remains. In MDI mode, when the tool change and interpolation statements are consistent (such as: "T2; M06; G01X200.0Y150.0; M30;" The phenomenon of test run is exactly the same as that under automatic mode. It was decided to further check the timer (TIMER), counter (COUNTER), data table (DATA) and holding relay (KEEPRL) on both sides of the PMCPRM parameters. The manufacturer did not provide complete standard parameters and specific comparison meanings. This section has an identical processing center of this type. Set the two equipment to the same mode and exclude them one by one with normal parameters as reference standards. It was found that K03 # 1=1 in KEEPRL; The normal K03 # 1=0; This type of data is usually used to define or support the implementation of a function. Under the condition of ensuring immediate shutdown, change this bit to "0" for commissioning. The machine tool returns to normal.