1, the tool method: CNC machining of the tool, the quality of its treatment directly affects the accuracy of the machining parts, but also affects the operation of CNC machine tools.
The so-called tool is in the workpiece coordinate system so that the tool point is located on the starting point (the tool point), so that under the control of the numerical control program, the machining surface cut by the tool has the correct size relationship with the positioning reference, so as to ensure the machining accuracy requirements of the parts. In NC machining, the basic methods of tool setting include test cutting method, tool setting instrument, ATC tool setting and automatic tool setting.
2, test cutting method: according to the position detection device used by the CNC machine tool, the test cutting method is divided into relative and absolute two kinds. In the relative test cutting method, three methods can be used:
One is to use measuring tools (such as steel ruler, etc.) to measure directly and align the size of the knife, this method is simple but not accurate;
Second, after the cutter point is aligned with the working face of the positioning block, the tool is removed to the tool size. The accuracy of this method depends on the accuracy of the tool point and the working face of the positioning block.
Third, the workpiece processing surface first light a knife, measure the size of the workpiece, indirectly calculate the size of the knife, this method is the most accurate. In the absolute test cutting method, it is necessary to use the reference knife, and then measure the other by direct or indirect methods
The deviation between the tool point and the reference tool is used as the set tool complement for other tools. The above test cutting method adopts the "test cutting - measurement - adjustment (compensation)" tool mode, so it occupies more time and has low efficiency, but because the method is simple and the auxiliary equipment is less, it is widely used in economic low-grade CNC machine tools.
3, the tool to the knife: the tool to the knife is divided into the machine to the tool to the knife and the machine to the knife. The tool is directly installed on a fixed position of the machine tool (for the lathe, the tool is directly installed on the tool holder or through the tool holder and then installed on the tool holder), this method is more commonly used in turning CNC machine tools.
The tool must be installed on the tool holder (lathe) through the tool clip, together with the tool clip, the tool is calibrated outside the machine in advance, and then the knife can be used on the machine tool, this method is currently mainly used for boring and milling CNC machine tools, such as machining centers.
The tool set needs to add the tool set auxiliary equipment, the cost is high, the loading and unloading of the tool is laborious, but it can save the tool set time and improve the tool set accuracy, and is generally used in CNC machine tools with high precision requirements.
4. ATC tool setting: AIC tool setting is a method to automatically calculate the length of the tool using the tool setting microscope on the machine tool. Because the tool setting mirror and the tool setting process are still manually operated and visually operated, there is still a certain tool setting error.
Compared with the tool tool, just loading and unloading the tool is more convenient and easy. Automatic tool setting is to use the tool detection function of the CNC device to automatically and accurately measure the length of each coordinate direction of the tool, automatically correct the compensation value of the tool, and directly process the workpiece without stopping.