Research Of Cutting Force Predicting And Surface Topography Based On Radius-variable Trochoidal Toolpath

Along with the high-speed milling technology unceasing development, making the machining accuracy and surface quality of workpiece has a higher request. For the weakness in Material remove rate and smoothness, there is always severe vibration and cutting force mutation in traditional milling tool path of high speed milling which will deteriorate the product quality. Especially in recent years, the proposal of trochoidal tool path is used to deal with the difficult part in the high speed roughing, which has been gotten more and more attention. But because of not perfect enough on characteristics of cutting force research and process theory, affecting the width and depth of its usage. So it’s the key problem in trochoidal milling that give full play to cutting force while ensuring the processing quality in trochoidal milling based on the intelligent analysis of the effect of cutting parameters on the surface morphology. In this paper, the cutting force and surface topography of radius-variable trochoidal milling is studied. Its main contents contain:Verify the significance of this paper by the comparison between the traditional processing methods and radius-variable trochoidal milling using two standard which is cutting force and surface topography on the new experimental platform. Confirm the advantages of trochoidal milling on cutting force and roughness by comparing with their tool path under the same conditions.Afterwards, an approach to predict cutting force of radius-variable trochoidal milling is proposed. Selecting the movement cycle of trochoidal milling as the research object, so the link between the engagement angle and the radial depth of cut can be easily obtained, then an equation of cutting force could be deduced by the differential element method. In addition, the maximum radial cutting depth strategy is proposed based on the prediction model. This strategy can maintain the stability of the cutting force, avoid the occurrence of impact load, and to a certain extent, help to promote the efficiency of processing.Based on the method of least square support vector machine, the surface roughness prediction model of radius-variable trochoidal milling is established by using the orthogonal experiments data. This model has simple structure, strong generalization ability, can very good solve problems such as nonlinearity, small sample and high dimension. The intelligent control of prediction model may offer mathematical foundation for optimization of the input parameters choice.From frequency field angle the power spectral density(PSD) was applied to characterize the ultra-precision machined surfaces. Combined with the conventional method and the power spectral density method not only express average statistics on the microscopic shape of components surface, but also can judge the direction of the surface features. The result shows that the combination which can describe quantitatively the distribution of super-smooth surface morphology in spatial frequency band, has the spectral description function and can provide abundant data for system analysis of ultra-presicison machining process, is of great guidance to the selection of manufacturing methods and process improvement.