Which parts are suitable for precision machining

Which parts are suitable for precision machining

We know that precision machining requires high precision. Precision machining has good rigidity, high manufacturing accuracy, and accurate tool alignment, so it can process parts with high precision requirements. So which parts are suitable for precision machining?

Firstly, compared to a regular lathe, CNC lathes have the function of constant linear speed cutting, which can be used to process both the end face and outer circles of different diameters at the same linear speed, ensuring consistent and relatively small surface roughness values. A regular lathe has a constant rotational speed, and the cutting speed varies depending on the diameter. When the material, precision machining allowance, and tool angle of the workpiece and tool are constant, the surface roughness depends on the cutting speed and feed rate.

When processing surfaces with different surface roughness, it is difficult to achieve good variability in ordinary lathes to choose a smaller feed rate for surfaces with lower roughness and a larger feed rate for surfaces with higher roughness. Parts with complex contour shapes. Any planar curve can be approximated by a straight line or an arc, CNC precision machining has the function of arc interpolation, which can process various complex contour parts. The quality of CNC precision machining requires careful use by operators.

Precision machining

CNC precision machining mainly includes processes such as precision turning, precision boring, precision milling, precision grinding, and grinding

(1) Precision turning and precision boring: Most precision light alloy parts (such as aluminum or magnesium alloys) in aircraft are processed using this method. Generally, natural single crystal diamond cutting tools are used, with a blade radius of less than 0.1 micrometers. Machining on a high-precision lathe can achieve a precision of 1 micrometer and a surface roughness with an average height difference of less than 0.2 micrometers, with a coordinate accuracy of ± 2 micrometers. Manufacturing and processing of non-standard precision components

(2) Precision milling: used for processing aluminum or beryllium alloy structural components with complex shapes. Relying on the accuracy of the machine tool's guide rails and spindle to achieve high mutual position accuracy. Accurate mirror surfaces can be obtained by using carefully ground diamond cutting heads for high-speed milling.

(3) Fine grinding: used for machining shaft or hole parts. Most of these parts are made of quenched and hardened steel, which has high hardness. Most high-precision grinding machine spindles use static or dynamic pressure liquid bearings to ensure high stability. The ultimate precision of grinding is not only affected by the stiffness of the machine spindle and bed, but also by factors such as the selection and balance of the grinding wheel, and the machining accuracy of the workpiece center hole. Fine grinding can achieve a dimensional accuracy of 1 micrometer and an out of roundness of 0.5 micrometers.

4. Grinding: Using the principle of mutual grinding of mating parts to select and process irregular protrusions on the machined surface. The diameter of abrasive particles, cutting force, and cutting heat can all be accurately controlled, making it a highly accurate machining method in precision machining technology. The hydraulic or pneumatic mating parts in the precision servo components of aircraft, as well as the bearing parts of the dynamic pressure gyroscope motor, are processed using this method to achieve precision of 0.1 or even 0.01 micrometers and micro roughness of 0.005 micrometers.

Die casting industry