When the machining center executes the machining program, the first tool is processed normally, but after the second tool is changed, the spindle and the workpiece collide during processing, and the machine tool cannot move after the collision. What is going on?
The above phenomenon may be related to the power supply and limit switch of the drive control board. Open the control cabinet, remove dust, and carefully check the wires, connectors and components for abnormalities. After testing, I found it to be X, Y, Z.
The power transistor GTK 457 on the 　　 drive board burned out. After replacing the damaged power tube, X, Y, Z.
The axis can move in three directions and manual tool change can be performed, but the tool change operation cannot be performed when the machining program command is executed. After the machine returns to zero, you can change the first tool, but the tool cannot be changed during the machining process. Based on experience, run the following tests in order.

1. TM 4 has proved that the Z axis shows ±0.02 by servo detection. It usually means that X is 0. 009-0.000 mm, Y is 0. 009?
   0.000 mm, Z is between 0.009 and 0.000 mm. This instruction indicates that the machine tool will not return to zero after the first tool is processed and the second tool is replaced.
   coordinate value is not between 0.009 and 0.000 mm. After changing the Z-axis detection accuracy parameter (also called machine positioning accuracy), set Z = 0. 050
   Well, the machine can work normally. However, on the machine, the other day, the other way around, the machine tool has discovered that it shows positive and negative X-axis, Y-positive, negative, and Z-axis positive and negative overtravel.
2. Check the circuit of the emergency stop button on the line and the machine. It is working properly. Check all the fuses. Even after the exchange, ensure that the FU4 (in the strong box) is burned out. The display when power is on is still the X axis and Y axis. , Z.
   Excessive axle travel. Please check the 24 V voltage on the power board, the output is normal, but there is no 24 V voltage when checking the Z-axis limit switch
   After checking the voltage input, it can be seen that this is a loose fuse. When you replace the fuse in the previous step, after tightening the fuse, but the power of the machine is operating normally, there is still a tool during the work. I will not exchange . According to experience, shut down the machine for 5 minutes
   After the power is turned on again, when the system is reset, the tool number will be changed at the same time, and the machine tool communication is normal.
   Second, develop solutions based on analysis reasons
3. After the machine collision, first check and replace the damaged parts of the X, Y, Z axis control board, and check whether the different parts of the machine work independently. The main reason for not replacing the tool is that the tool cannot be replaced, because the machine does not return to the original point when the second tool is replaced.
4. The three axes of the machine tool display overtravel at the same time, which means that there is no power in the stroke switch circuit of the control switch. Since the signal cannot be fed back to the control section, an overtravel alarm will be displayed.