The correctness of research methods and theories needs to be verified by relevant experiments. The experiment is divided into two steps. Firstly, the full NC end face hobbing method of spiral bevel gear and the NC gear cutting software are verified. In order to avoid the bad influence of the unreliable calculation method of gear cutting adjustment on gear cutting processing, the adjustment card calculated by Gleason cage software is used in the end face hobbing experiment of spiral bevel gear for the first time. The experimental object is a 14 / 47 cycloidal hypoid gear pair used in a bus. The cutting adjustment parameters and tool parameters of the controlled spiral bevel gear are calculated by Gleason cage software. The method is used to calculate the tool position of gear cutting. Figure 1 shows the tool position trajectory of each coordinate axis of the gear hobbing machine tool for controlling the end face of spiral bevel gear.
The NC machining program corresponding to the above machining tool position is generated by using the NC gear cutting software of controlled spiral bevel gear, which is used for the end face hobbing of controlled spiral bevel gear. Machining simulation shall be carried out before machining on the machine, so as to avoid the damage of tools and machine tools caused by wrong machining procedures. NC machining simulation software VERICUT is used for machining simulation. VERICUT is a NC machining simulation system developed by American CGTech company. It is composed of NC program verification module, machine tool motion simulation module, optimized path module, multi axis module, advanced machine tool feature module, entity comparison module and CAD / CAM interface. It can simulate NC lathes, milling machines, machining centers The NC processing process of various processing equipment such as wire cutting machine tools and multi axis machine tools can also optimize the NC program, shorten the processing time, prolong the tool life, improve the surface quality, check over cutting and under cutting, and prevent machine tool collision, over travel and other errors; It has a real three-dimensional solid display effect, can measure the size of the cutting model, and can save the cutting model for inspection and subsequent process cutting; With CAD / CAM interface, it can realize communication with UG Nested operation of CATIA, MasterCAM and other software. VERICUT software has been widely used in aerospace, automobile, mold manufacturing and other industries. Its biggest feature is that it can simulate various CNC systems, not only tool position files, but also NC programs processed by CAD / CAM. The whole simulation process includes program verification, analysis, machine tool simulation, optimization and model output.
The machining simulation platform of NC spiral bevel gear milling machine is constructed by using NC machining simulation software VERICUT. As shown in Figure 2a, the designed machine parts are converted into STL format model files in the three-dimensional design software, and then imported into VERICUT software for assembly. The assembly process is carried out according to the component tree arranged on the coordinate axis of the machine tool as shown in Fig. 2B. First, place the bed at the bottom, and the column is placed on the left side of the bed, which can move left and right, which is defined as the z-axis of the machine tool; A cutter head spindle slide plate is installed on the column, which can move up and down along the column, which is defined as the Y-axis of the machine tool; The cutter head spindle is installed on the cutter head spindle slide plate, which can rotate around the Z axis, which is defined as the c axis of the machine tool; The workpiece sliding plate is placed on the right side of the bed and can move back and forth, which is defined as the x-axis of the machine tool; The b-axis assembly is placed on the workpiece sliding plate and can rotate around the y-axis, which is defined as the b-axis of the machine tool; The workpiece spindle is placed on the b-axis assembly. When the b-axis is at zero degree, the axis direction of the workpiece spindle is parallel to the x-axis, which is defined as the a-axis. When assembling machine tool components, pay attention to the relative position relationship of each axis, and ensure that the origin of the machine tool is located at the intersection of the workpiece spindle and axis B. Figure 3 shows that all axes of the machine tool are in zero coordinates. At this time, the end face of the cutter head spindle is located in the xoy plane, and the cutter head axis and the workpiece spindle axis are located in the xoz plane, and both pass through the origin of the machine tool. After the mechanical part of the machine tool is assembled, add the virtual NC system control file as the control system of the machine tool, so that the machine tool can directly identify the NC program generated by the NC gear cutting software, and then the end face hobbing machining simulation platform is constructed.
