This paper analyzes the cause of tool collision fault of nc turning milling compound machine tool

Source: Huida Metal

Compared with ordinary machine tools, CNC turning and milling compound machine tools have high precision, good dimensional stability, low labor intensity and convenient for modern management. But due to improper operation or programming errors and other reasons, easy to make the tool or tool rest hit the workpiece or machine tool, light will hit the tool and be processed parts, heavy will damage the machine tool parts, so that the CNC turning milling compound machine tool processing precision loss, and even cause personal accidents.

The simulation machine is not locked. Because the CNC turning milling compound machine tool is locked by software, in the simulation processing, when pressing the automatic operation button in the simulation interface can not see whether the machine has been locked. There is often no tool to simulate, if the machine is not locked operation, it is easy to happen knife collision. Therefore, we should confirm whether the machine is locked at the operation interface before simulation processing.

Forget to close the empty running switch during processing. Because numerical control turn milling compound machine tool in the program simulation, in order to save time often open the empty running switch. Empty operation means that all axes of the machine tool are running at the speed of G00. If in the processing time and space operation switch is not off, the machine ignores the given feed speed, and runs at the speed of G00, resulting in a knife, machine accident.

No return to reference point after null run simulation. When checking the program, the machine is locked, and the tool relative to the workpiece processing in the simulation (absolute coordinates and relative coordinates in change), this time the coordinates and the actual position is not consistent, must be used to return the reference point method, to ensure that the mechanical zero coordinates and absolute, relative coordinates consistent. If a machining operation is performed without problems found after checking the program, it will result in a tool collision.

The overshoot was cleared in the wrong direction. When turning milling compound machine tool overrange, should press the overrange release button, with manual or hand way to move in the opposite direction, that can be eliminated. However, if the direction of lifting is reversed, it will cause damage to the machine tool. Because the overrange protection of the machine tool will not work when the overrange release is pressed, and the overrange protection stroke switch is already at the end of the stroke. At this time, it may cause the workbench to continue to move in the direction of the overrange, and eventually pull the lead screw, resulting in machine damage.

Improper cursor position at runtime for specified row. When a specified line is run, it is usually executed down from where the cursor is. For the lathe, the need to call the tool offset value of the tool, if there is no call tool, running the program section of the tool may not be the tool, it is likely to cause a knife collision accident due to different tools. Of course, in the machining center, CNC milling machine must first call the coordinate system such as G54 and the length of the compensation value of the knife. Because each knife length compensation value is not the same, if not called may also cause a knife collision.

Numerical control turning and milling compound machine tool as a high-precision machine tool, anti-collision is very necessary, requires the operator to develop a careful and careful habit, according to the correct method to operate the machine tool, reduce the occurrence of machine tool bumping phenomenon.