CNC machining seven kinds of tool detailed explanation - tool principle

Tool setting is the main operation and important skill in NC machining. Under certain conditions, the precision of the tool can determine the machining accuracy of the part, and the efficiency of the tool also directly affects the efficiency of CNC machining. Just know the tool method is not enough, but also know the various tool setting methods of the CNC system, as well as the call methods of these methods in the processing program, and know the advantages and disadvantages of various tool methods, use conditions, etc.

Tool setting principle

The purpose of the tool is to establish the workpiece coordinate system, the intuitive statement is that the tool is to establish the position of the workpiece in the machine table, in fact, it is to find the coordinates of the tool point in the machine coordinate system. For CNC lathes, the tool point must first be selected before processing, and the tool point refers to the starting point of the tool movement relative to the workpiece when the CNC machine tool is processed. The cutter point can be located on the workpiece (such as the design basis or positioning basis on the workpiece), it can also be located on the fixture or machine tool, if located on the fixture or machine tool at a certain point, the point must maintain a certain precision dimension relationship with the positioning basis of the workpiece.

When the tool is set, the cutter point should be made to coincide with the cutter point, the so-called cutter point refers to the positioning reference point of the tool, for the turning tool, the cutter point is the tip of the tool. The purpose of the tool is to determine the coordinate value of the tool point (or the workpiece origin) in the machine coordinate system and measure the tool position deviation value. The accuracy of tool point alignment directly affects the machining accuracy. In the actual processing of the workpiece, the use of a tool generally can not meet the processing requirements of the workpiece, usually to use more than one tool for processing. In the use of multiple turning tools processing, in the case of the same tool change position, the geometric position of the tool tip will be different after the tool change, which requires different tools to start processing at different starting positions to ensure the normal operation of the program. In order to solve this problem, the machine tool numerical control system is equipped with the tool geometric position compensation function, the use of tool geometric position compensation function, as long as the position deviation of each knife relative to a pre-selected benchmark knife is measured in advance, input to the numerical control system tool parameter correction column specified group number, the use of T instruction in the processing program, The tool position deviation can be automatically compensated in the tool path. The measurement of tool position deviation is also achieved through the operation of the tool.