Research On Image Expression Technology Of Complex Removal Volume Based On Tri-Dexel Model

In the NC machining process,the workpiece is cut by the tool,and the excess material is removed to process the workpiece.In the machining process,the part of the workpiece cut by the tool is called the removal volume.Researching removal volume is of great significance for researching real-time cutting force,cutting heat,improving machining accuracy,and improving machining efficiency.Because the relative motion between the workpiece and the tool is very complicated,the removal volume is an irregular complex polyhedron,it is not easy to store its geometric information,and it is not easy to be used to research the physical quantities such as cutting force and cutting heat,and the common cutting depth,cutting width and other geometric parameters cannot accurately and quantitatively describe the geometric characteristics of the removal volume.In view of the above problems,this paper proposes an image expression technology that can accurately and quantitatively describe the removal volume.First,the removal volume is calculated based on the method of Tri-Dexel model,and the short-distance continuous cutting motion in the machining is converted into the feed cutting of the subcutter location point,and the actual cutting of the workpiece by the tool is converted into Boolean operation of the tool and the workpiece Tri-Dexel model.A concept of radial cutting thickness is proposed to describe the geometry of removal volume.Radial cutting thickness refers to the distance at which the cutting point participating in the cutting at the current cutter location point is along the radius of the tool and the cutting tool participates in the machining process.Aiming at the problem that the discrete removal volume of TriDexel cannot directly calculate the radial cutting thickness,a method of constructing the virtual boundary of the removal volume Tri-Dexel model is proposed,and the radial cutting is calculated by calculating the distance between the intersection of the radial ray and the virtual boundary.Finally,the radial cutting thickness matrix is converted into a grayscale image.A two-dimensional grayscale image is used to describe the three-dimensional removal volume.The grayscale is used to represent the radial cutting thickness.The geometric shape of the removal volume is intuitively and specifically described..Finally,the calculation of the removal volume based on the Tri-Dexel model and the image expression technology were simulated and verified.Taking several typical shortdistance cutting as an example,the removal volume calculated based on the Tri-Dexel model is compared with the removal volume simulated by UG to verify the correctness of the above algorithm and the feasibility and accuracy of the image representation of the removal volume.