Prediction Research Of The Corner Milling Force Milling Hardened Steel Mold

Hardened steel mold has been widely used in the mold industry because of its excellent performance high strength, hardness and wear resistance especially in the automotive panel die. In today's rapid development of the world, with people's demand for cars is growing bigger and the shape of car requirements is higher, which forcing people need to understand the machining technology of hardened steel mold more deeply. The complexity and diversity of automobile panel makes die shape of the car more irregular, including corner shape. Ball end mill is widely used in the milling process of automotive mold.Therefore, this paper for ball end milling of hardened steel mold with corner shape were studied. Through the analysis of the die corner curvature is studied with the variation of milling ball milling force, the specific contents as follows:Firstly, the right angle and oblique cutting, cutting edge, screw lag angle and instantaneous undeformed chip thickness model are elaborated. Through the analysis of the relationship between the spiral lag angle and axial position angle, the function relation model of angle and axial position angle of lag angle between two vectors using spiral formula are established. Meanwhile, through single factor experiment and milling force coefficient groove cutting has been obtained through the linear regression method.Secondly, the effective feed per tooth and corner machining is analyzed basing on the processing characteristics of internal and external corner under fixed curvature, and a prediction model of milling forces based on machining feature is established. A corner milling three-dimensional finite element simulation model is established, and variation of ball end milling cutter and corner milling force is analyzed by comparison of the milling force in straight line, corner, outer corner milling. The inner and outer corner simulation of different radius of curvature is made based on the above theoretical analysis, then inside and outside corner milling force variation under the different curvature radius is obtained. The accuracy of the simulation result and model is verified by milling force experiment.Finally, inside and outside the corner cutting angle, radial residual height and feed per tooth under constant curvature and variable curvature is analyzed basing on the machining feature of fixed curvature corner, milling process variable model of fixed and variable curvature is established. The milling process models of two kinds of variable curvature are simulated, then the change rule of variable milling process with variable curvature is obtained and compared. The change rule of milling force with variable curvature is obtained through the corner milling experiment based on variable curvature. Research on tool system deformation is made, and the cutter deformation effecting on cutting angle and instantaneous undeformed chip thickness in the case of corner machining is analyzed, then prediction model of flexible milling force in corner machining is established.