Research And Application On NC Zero-programming For Gear Hobbing

With the requirement of higher quality, lower cost and shorter production period on gear manufacturing, it is significant to research on NC automatic programming with stable quality and convenient process. Traditionally, huge calculating work for manual programming leads to high error rate and low efficiency; while CAD/CAM automatic programming needs control information by manually obtaining model technics features, simulation and calculation, which inferences the programming quality and efficiency, with high cost and technical requirement of programmers.In order to solve the problem, the thesis proposes zero-programming technology, which generates Numeric Control (NC) programming automatically, by inputting certain parameters through human-machine interface and adopting technics and operation database. Hence, the workload and skill demand for the programmer is decreased, and the competitive power of the machine tool is improved, with high efficiency, low cost and stable production quality.Zero-programming in gear hobbing is researched and applied in the thesis. Firstly, the frame work of NC zero-programming system for hobbing was studied based on analyzing technology feasibility. And then the zero-programming mathematic models on hobbing for cylinder, bevel and crown gears were established, including hobbing route, cutting stroke, cutter channeling and parameter calibration.After that, zero-programming system for gear hobbing based on open architecture SINUMERIK 840D was developed. The human-machine interface, data communication as well as other function modules were designed using VB, VC++, OEM package and Dynamic Data Exchange (DDE) technology.Finally, the developed system was tested and applied in gear hobbing machine tool, with real-time display of field data, technics inquiry and parameter verification. It has validated the system of high efficiency, safety, and stable quality. Zero- programming method can be used in NC process with fixed and limited parameters, such as gear grinding, gear shaper, and manufacturing of axis and disc parts.