1. Part installation and positioning
Install the NC turntable in the middle of the workbench of the vertical machining center, install the fixture on the turntable, install the parts on the fixture, align the positioning pin on the fixture with a tooth slot of the parts, then clamp the parts and exit the positioning pin.
2. Tool setting
The machining program generated by the secondary development of NX software is imported into the vertical machining center, and the tool setting is carried out according to the tool setting method of NC machine tool. The right-hand driving bevel gear is based on the concave tooth surface. The tool center and the connecting line between the tool center and the face cone center when cutting the convex tooth surface form an included angle. The included angle is compared with the included angle generated by the model to adjust the milling position of the convex tooth surface. For the left-hand driven bevel gear, the tool setting is based on the convex tooth surface, the tool setting angle of the machine tool and the model is compared, and the milling position of the concave tooth surface is corrected, and other quantities remain unchanged.
3. Commissioning
Run the program for trial cutting, and adjust the processing parameters according to the surface roughness of trial cutting parts and tool wear. Other error compensation according to the size error: helix angle correction, modify the machine code for correction; The chamfer size is determined according to the offset of the corrected a-axis and z-axis, or according to the corrected tool length compensation.
The whole process is divided into tool cut in – cutting – tool cut out – indexing, which is carried out in a cycle. During cutting, the position of the machine tool in the Y-axis and z-axis directions remains unchanged, only moves in the x-axis direction, and the turntable rotates the a-axis at the same time; When the cutter cuts in and out, the spindle moves in the z-axis direction; When indexing, the spindle position remains unchanged. Trimming processing test is shown in the figure.