- Install the tool
The CKA6150 CNC lathe used to process the bearing sleeve is a six-station automatic tool post. When installing the tool, the height of the tool tip and the center line of the spindle must be adjusted. The adjustment method is to add a gasket. The extension length of the arbor should be 1.5 to 2 times the thickness of the arbor.
The general principle of tool installation is: tools with similar functions should be installed nearby, and the process switching and tool replacement should be completed in a relatively short time.
- Install the workpiece
CNC lathes generally use three-jaw self-centering chucks, and the installation and alignment of workpieces are basically the same as those of horizontal lathes. When the round bar material is clamped, it should be placed horizontally in the jaws of the chuck, and after correction, tighten the wrench of the chuck, and the workpiece clamping and alignment will be completed immediately.
- Knife setting
The tool position point is the reference point of the tool.
The tool setting point is the point used to determine the relative positional relationship between the tool and the workpiece, and is the point used to determine the workpiece coordinate system and the machine tool coordinate system. Tool setting is to place the tool position point of the tool on the tool setting point in order to establish the workpiece coordinate system.
The principle of selecting the knife point:
(1) The selected tool setting point position should be convenient for mathematical processing and simple programming
(2) Easy to align on the machine tool
(3) Easy to check during processing
(4) The processing error caused is small
Tool setting is the main operation and important skill in CNC machining. Under certain conditions, the accuracy of tool setting can determine the machining accuracy of parts. At the same time, the efficiency of tool setting also directly affects the efficiency of CNC machining.
- Tool setting is generally divided into two categories: manual tool setting and automatic tool setting. At present, the vast majority of CNC machine tools (especially lathes) adopt manual tool setting. The basic methods are: positioning tool setting method, optical tool setting method, ATC tool setting method and trial cutting tool setting method.
The commonly used tool setting method in FANUC CNC system is the trial cutting tool setting method with tool offset compensation. The steps are as follows:
(1) Use the external turning tool to test an external circle, exit along the +Z axis and keep the X coordinate unchanged. Measure the diameter of the outer circle and record it as d.
(2) Press the “OFSET SET” key → enter the “shape” compensation parameter setting interface → move the cursor to the position corresponding to the tool position number, enter Xd, press the “measurement” key, the system Automatic calculation of tool offset in X direction
(3) Test the end face of the workpiece with an external turning tool, exit along the +X axis and keep the Z coordinate unchanged.
(4) Press the “OFSET SET” key → enter the “shape” compensation parameter setting interface → move the cursor to the position corresponding to the tool position number, enter Z0, press the “measurement” key, and the system automatically calculates Z Direction tool offset. You can also “input” the offset yourself.
(5) The set tool offset is called with T code in the NC program.
This method has the advantages of easy to understand, simple operation, programming and tool setting can be completely separated. Therefore, it is most commonly used in tool setting.