Research On The Cutting Geometry Model Of Five-Axis Milling With The Toroidal Cutter

With the development of manufacturing technology,CNC machines,as high-end manufacturing equipment,have been widely used in aerospace,automotive manufacturing,electronic energy,mold processing and so on.Among them,five-axis CNC machine has been favored in the high-end manufacturing industry because of its flexible position,attitude processing,higher machining accuracy and efficiency,lower processing costs and other advantages.In the five-axis CNC machining process,the cutting force is one of the important parameters of the cutting process parameters.Cutting force prediction provides a theoretical basis to the selection of the appropriate amount of cutting and cutting tool geometry parameters and improving the cutting life of the tool,and ultimately provides a scientific basis for the realization of high-speed and high-precision digital manufacturing technology.At present,most researches on cutting force in CNC machining process are the vertical milling based on the ball milling cutter.However,there are few researches on the cutting force of five-axis CNC milling with the toroidal milling cutter.In this paper,the cutting force and the extraction of cutter-workpiece engagement are studied in the five-axis NC milling process.The main research content and innovations are as follows:First of all,an algorithm for judging the concavity of instantaneous free-form surface is proposed in a five-axis NC machining.In the global coordinate system,the free-form surface is discretized.The circular cutter on the torus and the bottom end face,cylindrical tangent point are respectively taken as the reference points,which are projected onto the rough or rough surface along the global coordinate system as the two reference lines in order to judge the concavity of instantaneous free-form surface.The algorithm proposed in this paper can be applied to five-axis CNC machining process of concave,convex,flat,oblique and other free-form surface,with better practicability.Then,the model for obtaining the cutter-workpiece engagement isestablished in the process of five-axis machining with the toroidal cutter.Without considering the tool interference,the traditional envelope surface method,the discrete-analytic method and Unigraphics NX are used to obtain the engagement between the tool and the workpiece in five-axis machining,that is,to obtain the entry and exit angles angles of the tool in different rotation angles.Compared with the traditional analytical method,the proposed model greatly reduces the computational workload,but also guarantees the accuracy requirements.Finally,according to the cutting force in the five-axis machining process,the application of the cutting geometry in the cutting force in the five-axis machining of the annular milling cutter is analyzed.Using Unigraphics NX to simulate the cutting force on the free form surface,and predict the cutting force in the five-axis machining plane under different inclination angles.Using the Kistler 9257 B to measure the cutting forces in three directions in the local workpiece coordinate system,the 2825A-02 Dyno Ware will be used to collect the cutting force.The data is recorded.Finally,it is proved that the cutting geometry model proposed has certain usability.