Subregional Process Method With Variable Parameters Based on a Potential Field in Slow Tool Servo Machining for a Complex Curved Surface

Precision turning with slow tool servo (STS) plays an increasingly important role in advanced manufacturing nowadays. However, it is difficult to promote machining quality for surfaces with local complex geometric features by the conventional global machining method. Hence, a subregional processing method in STS is proposed. First, the continuous equipotential line is taken to express the local geometric feature. Thus, a potential field is built, where the surface could be divided into subregions. Then, a subregional toolpath with variable feed rates is generated by the field and stitched to ensure the feeding motion stability of X-axis. Finally, the surface is subdivided for variable spindle speed planning, considering the feeding motion stability of Z-axis. It is found that the profile arithmetic average error reduces by 31.58% with the proposed method compared with that with the conventional method and the machining time is shortened by 41.00%. Thus, it is proved that the new processing method effectively promotes machining quality and efficiency.

Ultra-Precision Single-Point Diamond Turning of a Complex Sinusoidal Mesh Surface Using Machining Accuracy Active Control

Single-point diamond turning (SPDT) assisted with slow tool servo (STS) is the most commonly utilized technique in the fabrication of optical modules. However, the tool path significantly affects the quality of the machined surface. In order to realize the determined machining accuracy effectively, a tool path generation (TPG) method based on machining accuracy active control (MAAC) is presented. The relationship between tool path and machining error is studied. Corner radius compensation (CRC) and the calculation of chord error and residual error are detailed. Finally, the effectiveness of the proposed approach is verified through a machining error simulation and a cutting experiment of a complex sinusoidal mesh surface fabrication.

Machining precision controlling method for plane surface assisted by SPDT

In traditional processing mode, a given lathe and a set of fixed processing system can only produce a predetermined precision part. This article proposes a machining method that can control the surface precision of machining plane parts, and four gaskets with different accuracy requirements are processed on the same slow tool servo single-point diamond lathe for experimental verification. Then, the Peak Village (PV) value and surface topography of the processed parts were measured using the surface profiler Taylor Hobson PGI 1240 and Keyence VR-3200, respectively. Through the processing and analysis of the measured data, the maximum deviation between the PV value and the given PV value is 2.4 µm, the minimum deviation is 0.4 µm. And the PV value obtained by calculating the helical spacing measured by surface topography according to the method in this article is approximately equal to the measured PV value, so the correctness of the machining method is verified. Therefore, the machining method can control the surface accuracy of machining parts accurately according to the required accuracy.