Compared with ordinary machine tools, CNC machine tools have the following characteristics.
(1) Strong adaptability, suitable for processing single or small batch of complex workpieces. CNC machine tools can process many complex surface parts that are difficult or impossible to process with ordinary machine tools, such as propellers. This is because the CNC machine tool has the function of multi-axis linkage, and the tool can move along the space curve trajectory. Therefore, CNC machine tools are first used in aerospace and other fields, and are also widely used in the processing of complex curved molds, propellers and turbine blades. When changing the processing parts on the CNC machine tool, only the corresponding processing program needs to be changed to process the new parts without the need to manufacture or replace many tools and fixtures, nor to readjust the machine tool. Therefore, CNC machine tools are particularly suitable for the processing of single parts, small batches and trial production of new products.
(2) High processing accuracy and stable product quality. The transmission parts of the CNC machine tools, especially the ball screw, have high manufacturing accuracy, eliminate the transmission gap during assembly, and adopt measures to improve the rigidity, so the transmission accuracy is very high. The guide rails of CNC machine tools use rolling guide rails or have friction resistance, which eliminates low-speed crawling. The closed-loop and semi-closed-loop servo systems are equipped with high-precision position detection elements, and the position errors are fed back to the computer at any time, so that they can be corrected in time, so that the CNC machine tool obtains high processing accuracy. In addition, the machining process of the CNC machine tool is completely automatic, which is to eliminate the operator-generated errors, make the dimensions of the same batch of parts consistent, and the processing quality is very stable.
High productivity. The time required for parts processing includes motor time and auxiliary time. CNC machine tools can effectively reduce these two parts of time. The speed adjustment range of the spindle speed and tool feed speed of the CNC machine tool is larger than that of the ordinary machine tool, and the machine tool has good rigidity. The rapid movement and stop adopt acceleration and deceleration measures, which can not only increase the speed of the empty stroke movement, but also ensure the positioning accuracy, and effectively reduce the maneuvering time. Because of the high positioning accuracy of CNC machine tools, the number of shutdown detections is reduced, and the processing preparation time is also shortened by the use of general-purpose tool fixtures, thereby reducing the auxiliary time. According to statistics, the productivity of CNC machine tools is 2 to 3 times higher than that of ordinary machine tools. When processing some complex parts, the productivity of CNC machine tools can be increased by dozens or dozens of times.
Reduce labor intensity and improve working conditions. CNC machine tools are mainly automatic processing, which can automatically change tools, switch cutting fluid, automatic speed change, etc. Most of their operations do not require manual completion, thus improving working conditions. Due to the reduction of operational errors, the scrap rate and defective rate are also reduced