One is the design of machine toolsThis is the soul of machine tool accuracy. Japanese machine tools may not seem special, but they have high accuracy and durability. High precision machine tools have a perfect grasp of design details.
Secondly, machine tool castingsA machine tool casting is a skeleton, which is the key to withstand cutting torque force and dispersed vibration force, and is the foundation for the stability of the entire machine. High precision machine tools, without good castings, even the best spindle screw guide rail, the accuracy of the entire machine will disappear after a year. The third is that the system determines the key accuracy of the machine toolConventional imported systems include Fanuc, Mitsubishi, Siemens, Heidelberg, and Rexroth, while domestically produced systems include Guangshu and Huazhong CNC. Most machines have Fanuc. The Fanuc system is widely used in gantry, horizontal, vertical, lathe, sheet metal machine tools, and even robots.The accuracy of a machine tool refers to the accuracy of the shape, mutual position, and relative motion of its main components, including geometric accuracy, transmission accuracy, motion accuracy, positioning accuracy, and accuracy retention. Various types of machine tools can be divided into ordinary precision level, precision level, and high-precision level according to their accuracy. The above three accuracy levels of machine tools all have corresponding accuracy standards, and if the tolerance is 1 for the ordinary level, the approximate ratio is 1:0.4: 0.25. In the design phase, the main focus is on improving the accuracy of the machine tool in terms of accuracy allocation, component and material selection.Geometric accuracy refers to the accuracy of the shape, mutual position, and relative motion of the main components of a machine tool under no-load conditions, without movement (such as when the machine tool spindle does not rotate or the workbench does not move) or at low motion speeds. For example, the straightness of the guide rail, the radial runout and axial movement of the spindle, and the parallelism or verticality of the spindle centerline to the direction of sliding table movement. Geometric accuracy directly affects the accuracy of processed workpieces and is a basic indicator for evaluating the quality of machine tools. It mainly depends on the quality of structural design, manufacturing, and assembly.Motion accuracy refers to the accuracy of the main components of a machine tool when moving at the speed of their working state. The rotation accuracy of high-speed rotating spindle. For high-speed and precision machine tools, motion accuracy is an important indicator for evaluating the quality of the machine tool. Motion accuracy and geometric accuracy are different. It is also influenced by the speed of motion (rotational speed), the gravity of the moving parts, transmission force, and friction force. It is related to factors such as structural design and manufacturing.Transmission accuracy refers to the coordination and accuracy of relative motion between the end effectors of a machine tool transmission system. This error becomes the transmission error of the transmission chain, such as when the lathe is turning threads, the movement of the tool holder should be equal to the lead of the dry thread for each revolution of the spindle. But in fact, due to the error in the transmission chain between the spindle and the tool holder, the actual displacement of the tool holder and this error are the transmission errors of the lathe thread transmission chain. The transmission accuracy is determined by the design of the transmission system, the existence of errors in the ideal displacement, and the manufacturing and assembly accuracy of the transmission components.
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