Geometric Modeling And Tool-path Planning For NC Flank Milling Of Blower Impeller

The impeller of blade is kind of parts of complex shape. Simultaneously this kind of components is also turbine machine's key component. Impeller's processing quality directly affects the complete machine's power performance and the mechanical efficiency.The surface of the blades of the impeller is usually complex. Accordingly the impeller is this kind of part in the production, whose geometry characteristic is obvious, and which actually has certain representative. When we design the impeller, we should analyze and control the impeller interior fluid. Whether the design target meets the requirement, manufacturing chain needs to be guaranteed. It is impossible to complete by 3-axis nc machining, but must use 5-axis nc machining. At present, lacking understanding to the complex geometry relations between the cutting tool and the components of 5-axis nc machining causes 5-axis nc machining was still a difficult problem. If the technique of manufacture is weak, impeller's overall performance will certainly to be affected. Therefore this research from the cutting tool and components geometry angle embarking is very meaningful.Impeller's surface modeling is the foundation and safeguard of accurate machining of the impeller. The tool-path planning is the most important content in the complex impeller parts NC machining. Therefore, the impeller's geometric modeling and optimizing the tool-path of the 5-axis nc flank milling is the key content.The impeller's accurate modeling plays a crucial role in NC machining. This article applies the inverse calculation of cubic B-spline in data points of the blade top and the blade root of the blade neutral surface, which are given by the drawing, to construct blade surface of non developable ruled surface .Carry on solid modeling of integral impeller based on UGNX4₀ software.Based on the geometric modeling, plan the cutter path of the NC flank milling impeller. Firstly, transform the range between the blade curved surface machined and cylindrical tool miller envelope into that between the offset surfaces of the blade curved surface machined and cutter shaft path surface. Because there is range transfer between the two offset surfaces, which has brought conveniently for the tool-path planning. Then the tool-path planning's optimization sums up in the offset surface of the blade curved surface machined and cutter shaft path surface. Based on three propositions, a global optimization theory of tool positioning is described in detail. A positioning strategy of cylindrical cutter with least square is presented.Based on using free-surface modeling technique and tool-path planning, calculate the error between the cutter shaft path surface and the designed surface. The method obtains satisfactory approximation accuracy, which has the certain theoretical significance and practical value.