1. Software preparation
The secondary development is carried out on the basis of NX software, and a small plug-in is designed. Different models can be obtained by inputting the adjustment parameters of the machine tool for the actual machining of spiral bevel gears. The three-dimensional data of a tooth surface of the actual product is collected and compared with the established model. The error is basically within 0.1mm.
Continue to input chamfer parameters and milling cutter parameters, supplemented by simple human-computer interaction operation, you can get the machining G code of tooth top trimming of spiral bevel gear. The parameters to be input include the number of large and small teeth, modulus, pressure angle, helix angle, tooth width and gear blank. These parameters can be obtained directly from the drawing, and the calculation results can be read directly by NX software.
2. Hardware preparation
2.1 Turntable and installation
The turntable has two NC axes: swing axis and rotating axis. Only the swing axis is linked with the machine tool. In order to ensure the machining accuracy and efficiency, in the bevel gear trimming scheme, the rotating shaft carries out indexing movement without linkage with the machine tool; The swing shaft is linked with the machine tool to make the cutting point always on a plane. The NC turntable is shown in Figure 1.
2.2 Fixture design and manufacturing
According to the conditions of machine tool, turntable and parts, two sets of hydraulic fixtures for test are manufactured, and the fixture is equipped with locating pins to determine the cogging position of parts, as shown in Figure 2. The hydraulic fixture can automatically clamp the workpiece, eliminate the gap between the fixture and the workpiece and locate accurately, so as to ensure that the workpiece is clamped in place and the consistency of processed parts is good.
2.3 Tool selection
Two kinds of cutting tools are selected for experimental processing. One is finger chamfering cutter, with bevel gear taper of 45 ° and diameter of ϕ １６ ｍｍ； The other is a two edge ball head cemented carbide milling cutter with a diameter of ϕ 12mm is a standard ball end milling cutter, as shown in Figure 3.
