Experimental Study On The Critical Condition Of Natural Chip Splitting During V-shaped Tool Cutting

Machining processing is a high energy consumption industry,and cutting tool as an important mechanical and electrical products, its energy consumption was very high in the processing,which resulted a large number of energy waste,lower cutting efficiency and deterioration of cutting conditions.However,Chinese tool industry didn’t pay enough attention to energy-saving technology of cutting tool,the design and manufacture of the cutter mainly based on the experience of imitation and calculation,which didn’t include advanced tool structure design and cutting theory. In the actual cutting process,the cutting force and cutting energy consumption would be significantly reduced when the chip occurred natural chipsplitting, so if the mechanism of natural chip-splitting is used in the actual tool design, it will help to reduce the cutting force and energy consumption, improve the cutting efficiency and cutting condition,improve the competition of national cutters. However, the research on natural chip-splitting has not been paid enough attention by people.In this paper, mathematical model of V-shaped tool’s chip-removal vector had been established to find the influencing factors of chip-splitting, and found the critical condition for natural chip-splitting of different materials by multi level and multi factor experiments,and verify the accuracy of the conclusion though thread turning experiment.The main contents are as following:First of all,the theory of non-free cutting and the mathematical modeling of chip removal vector were introduced, and mathematical model of V-shaped tool’s chip-removal vector was established,which built the foundations for the determination of the experimental factors and the calculation of the coefficient of non-degree of freedom;Furthermore,according to the cradical condition of natural chip-splitting for the cutting parameters and tool geometry was complicated surfaces during V-shaped tool cutting and the cutting parameters&the geometric angle of the cutter were difficult to change continuously,a method was proposed for reduced the reasonable ranges for cutting parameters and the geometric angles of the cutting tool in the experiment,and to obtain the relatively accurate ritical surface of natural chip-splitting by multi- round experiment.Then, multi- round experiment for V-shaped tool cut 45 steel and 304 stainless steel were designed,fitted the corresponding empirical formula and curved surface for the cradical condition of natural chip-splitting, explored the influences of tools’ geometric angle and cutting parameters on chip-splitting,and through elementary tools cutting experiment proved that Vshaped tool cuttingunder chip-splitting was “Free cutting”under chip-splitting.At last, A set of triangle thread turning experiment was designed with different cutting tool geometry, cutting depth and the same cutting speed, pitch,which had verified the generality of the conclusions obtained.