CNC machine tools in the processing process, often appear appearance is not beautiful phenomenon, the appearance of several characteristics including surface roughness, surface wave, surface processing grain several aspects. Surface roughness is the basic unit that constitutes the characteristics of machining surface. When machining the surface of the workpiece with a metal cutting tool, the surface roughness is mainly affected by the effects and effects of several elements, physical elements and mechanical processing process elements.

1. How many elements

From several viewpoints, the shape of the tool and several viewpoints, especially the radius of the tool tip, the main declination Angle, the auxiliary declination Angle and the feed amount in the cutting parameters have a great influence on the surface roughness.

2. Physical elements

Considering from the physical nature of the cutting process, the rounded edge of the tool and the kneading and conflict behind the tool cause plastic deformation of the metal material, which seriously worsens the surface roughness. When the plastic material is processed to form a strip chip, the chip nodules with high hardness are simply formed on the front tool surface. It can replace the front tool face and cutting edge for cutting, so that the number of viewpoints of the tool and the amount of back cutting tool can be changed. The summary of the chip tumor is very irregular, so that the surface of the workpiece shows the depth and width of the knife mark are constantly changing. Some chip nodules are embedded in the surface of the workpiece, which increases the surface roughness.

The oscillations during the cutting process increase the surface roughness parameter value of the workpiece.

3. Process elements

Considering its influence on the surface roughness of the workpiece from the point of view of the process, there are mainly factors related to the cutting tool, the factors related to the material of the workpiece and the factors related to the processing conditions.

The surface quality of the cut workpiece has a great influence on the performance of the parts. The main characteristics of measuring the surface quality of the workpiece are surface roughness, surface residual stress and surface work hardening degree. In the characterization of the parts of the surface quality of the three objectives, the most important effect on the performance of the part is the surface roughness of the workpiece.

The surface roughness of the parts directly and obviously affects the conflict and wear, the rougher the surface, the more severe the wear. At the beginning of wear, the micro-convex peak of surface roughness is quickly worn down, and the wear amount rises quickly. After a period of work, the touch area between the moving surfaces increases, and the speed of wear will slow down. If the surface lubrication is fine, the height and sharpness of the microscopic convex peak are smaller, so the surface of the fine lubrication is wear-resistant than the rough surface.

However, the appearance is too lubricated, which is not conducive to the storage of lubricating oil, but will increase the conflict coefficient of the appearance, and cause the metal appearance to heat and "gluing" phenomenon. In the vertical machining center cutting process, cutting speed, feed and cutting depth and other process parameters will affect the cutting force, cutting force and cutting temperature are two interrelated factors, usually the greater the cutting force, the higher the cutting temperature, the more fierce the oscillation of the vertical machining center.
The cutting speed is different, the outside world encourages the frequency of mechanical processing equipment oscillation is different, the frequency and the vertical machining center oscillation natural frequency closer, the more simple the mechanical equipment oscillation intensification.

In order to obtain more ambitious surface roughness value of the workpiece in the cutting process, a set of cutting force and cutting temperature detection system is designed to study the relationship between the cutting force, cutting temperature and the surface roughness value of the workpiece. In the cutting process, the cutting force, cutting temperature and mechanical equipment oscillation are controlled by selecting the appropriate cutting speed, feed rate, cutting depth and other process parameters, and then the required surface roughness value of the workpiece is obtained.