How to avoid accidents of tool collision in large CNC machining centers

Manufacturers of large CNC machining centers or enterprises engaged in machining often hear about accidents where machining centers collide with knives. If operators do not comply with safety operating procedures, personal or equipment accidents may occur. In CNC machining centers, because most of them are equipped with safety doors, it is required to close the safety doors during processing, and the operator does not directly operate the machine tool, so the probability of personal accidents is very low.

However, the probability of equipment accidents is much higher than that of other mechanical processing, because ordinary machine tools are processed manually by operators relying on their own operating experience; CNC machining centers automatically control machine tools for machining through machining programs. Large CNC machining centers are not directly controlled by humans, but are controlled by programs.

1. User:
Technicians often make programming errors, input errors, and corrections when operating machine tools, as well as coordinate system or tool compensation errors. Carelessness in operating machine tools can lead to tool collision accidents. If there is a phenomenon of tool collision during the use of the machining center, it will not only bring great psychological pressure to the operator, but also cause certain economic losses. So, how can we avoid it?

2. Manufacturer:
Due to the high price, difficulty in maintenance, and high cost of machining centers, and the high precision, efficiency, and automation of machining parts mainly rely on the accuracy of machine tools. Once equipment accidents occur, the accuracy of machine tools will be severely reduced. In fact, the occurrence of tool collision accidents has a rule to follow. As CNC machining centers are locked using software, during simulation processing, when the automatic operation button is pressed, it is not visually visible on the simulation interface whether the machine tool has been locked.

During simulation, there is often no tool alignment. If the machine tool is not locked during operation, it is easy to collide with the tool. Therefore, before simulating processing, it is necessary to confirm whether the machine tool is locked at the operation interface. Forgot to turn off the air transport switch during processing. Due to the fact that during program simulation, the idle running switch is often turned on to save time.

When the machining is running in simulation (with changes in absolute and relative coordinates), the coordinates do not match the actual position. It is necessary to use the method of returning the reference point to ensure that the mechanical zero point coordinates are consistent with the absolute and relative coordinates.

When the machine tool overtravels, the overtravel release button should be held down and moved in the opposite direction manually or manually to eliminate it. But if the direction of release is reversed, it will cause damage to the machine tool. Because when the overtravel release is pressed, the overtravel protection of the machine tool will not work, and the travel switch of the overtravel protection is already at the end of the travel.

 

At this point, it is possible to cause the workbench to continue moving towards the overtravel direction, ultimately damaging the lead screw and causing damage to the machine tool. When running on a specified line, it is often executed downwards from the position of the cursor. For a lathe, it is necessary to call the tool offset value of the tool used. If the tool is not called, the tool running the program section may not be the desired tool, which is highly likely to cause tool collision accidents due to different tools. Of course, on machining centers and CNC milling machines, it is necessary to first call the coordinate system such as G54 and the length compensation value of the tool. Because the length compensation value of each knife is different, if not called, it may also cause a knife collision.

In short, mastering the programming skills of the machining center, using various methods to verify the program, coordinate system and tool length compensation, radius compensation settings are correct, and the operation process is done in a visual and auditory manner to avoid unnecessary errors. This can effectively avoid the occurrence of tool collision and better protect the CNC machining center. ​