The tool location point is a datum point on the tool, and the relative movement track of the tool location point is the processing path, also called the programming track.
Tool setting means that the index control operator passes certain measuring methods to make the tool position point coincide with the tool setting point before starting the CNC program. You can use a tool setting instrument to measure the tool, its operation is relatively simple, and the measurement data is relatively accurate. You can also use the gauge block, feeler gauge, dial indicator, etc. to set the tool using the coordinates on the CNC machine tool after positioning the fixture and installing the parts on the CNC machine tool. For the operator, it is very important to determine the tool point, which will directly affect the machining accuracy of the part and the accuracy of the program control. In the batch production process, the repeat accuracy of the tool setting point must be taken into account. The operator must deepen the understanding of the numerical control equipment and master more tool setting skills.
Simple alignment on the machine tool, easy to check during processing, easy to calculate during programming, and small error in tool setting.
The accuracy and precision of the forward tool setting, even if the parts require low precision or the program requirements are not strict, the machining accuracy of the selected tool setting part should be higher than the machining accuracy of other directions.
As much as possible, the tool setting point is consistent with the planning reference or process reference, so as to avoid the reduction of tool setting accuracy or even machining accuracy due to standard conversion, and increase the difficulty of CNC program or part CNC machining.
The accuracy of tool setting points not only depends on the accuracy of CNC equipment, but also depends on the requirements of parts processing. Manually check the accuracy of tool setting to advance the quality of parts in CNC machining. Especially in batch production, the repetitive accuracy of the tool setting point should be considered. The accuracy can be checked by the coordinate value of the tool setting point relative to the machine origin.
Regarding numerical control equipment such as numerical control lathes or turning and milling machining centers, since the center position (X0, Y0, A0) has been determined by numerical control equipment, the entire processing coordinate system can be determined by determining the axial direction. Therefore, it is only necessary to determine an end face of the axial direction (Z0 or relative orientation) as the tool setting point.
Regarding four-axis or five-axis CNC equipment, the 4th and 5th rotary axes have been added, which is similar to the selection of tool setting points for three-axis numerical control equipment. As the equipment becomes more messy, the CNC system is also intelligent and provides more tool setting methods. , According to the specific numerical control equipment and specific machining parts, the coordinate connection of the tool setting point relative to the machine tool coordinate system can be simply set to be related to each other. For example, the coordinates of the tool setting point are (X0, Y0, Z0), which are the same as the machining coordinate system Contact can be defined as (X0+Xr, Y0+Yr, Z0+Zr), and the processing coordinate system is G54, G55, G56, G57, etc., which can be input through the control panel or other methods. This method is very flexible and highly skilled, which brings great convenience to subsequent CNC machining.
(3) The main reasons for bumps:
b. The standard and other related standard input errors of the workpiece and the initial position positioning error of the workpiece;
Therefore, the operator must pay special attention to the initial stage of the execution of the program and the time when the machine is replacing the tool. At this moment, once the program is modified incorrectly, the diameter and length of the tool are input incorrectly, then a collision will easily occur.
In order to avoid the above-mentioned bumps, CNC operators should give full play to the functions of the five senses when operating the machine tool, and investigate whether the machine tool has abnormal movements, sparks, noise and abnormal noise, sensation, and burnt smell. If an abnormal situation is found, the program should be interrupted immediately. After the standby bed problem is solved, the machine tool can continue to operate.
