| In order to improve the machining efficiency of turbine blade profile,a surface shaping technology for turbine twisted blade profile is proposed,which is implemented on a self-built surface shaper.Firstly,starting from the characteristics of the torsion blade profile,the cutting direction,the type of cutting tool,and the cutting motion are planned.Then,the layout of the shaper for the twisted blade of steam turbine is determined based on them,which lays a foundation for further research.The main motion of shaper is driven by the ordinary hydraulic cylinder,and the CNC system realizes multi-axis linkage by measuring the coordinate values of the main motion axis by encoder and correspondingly controlling the servo motors of each axis.Secondly,the data points of twisted blade are transformed into a surface model to generate the cutter-contact path.By taking the characteristics of shaping process into consideration,the cutter contact points are converted into cutter location points according to specific methods,and the appropriate tool orientation is selected to avoid interference.Considering that there is no suitable software precedent of postprocessing for shaping,this paper post-process the cutter location data by its own method,and completes the design of tool path.Thirdly,the hardware and software architecture of shaping CNC system is built,and the software functions required for shaping process are realized through the secondary development of software.The multi-axis follow-up function is a special interpolation function for shaping process.Its sub-function follow-up interpolation function takes the high-speed characteristic of shaping into account in interpolation principle and adopts the curve direct interpolation method.Although the curve direct interpolation method overcomes the problem of out-of-step in interpolation of data sampling method,its operation process involves solving the non-linear equation,which puts forward higher requirements for the real-time performance of CNC.For this reason,the speeds of three methods of solving the non-linear equation are compared by experiment,the suitable method of solving the non-linear equation is chosen,and the vector calculations involved are simplified,which makes the speed of interpolation meet the real-time performance requirement.Finally,the surface shaping technology for turbine twisted blade profile is validated by machining experiments.The machined surface is the same as the twisted blade profile model,which proves the correctness and rationality of the surface shaping technology for turbine twisted blade profile. |
PDF Full Text Request