Research On Robotic Belt Grinding Of Precision Casting Blade Based On 3D Measurement Technology

Aircraft engine blades are the important parts of aircraft engines,and their manufacturing efficiency and quality will determine the performance and life span of aircraft engines.At present,for high precision turbine blades and special hollow blades,the domestic generally adopts precision casting,high-precision milling,manual experience grinding polishing,or special CNC machine grinding and off-line measurement combined manufacturing process.Among these methods,the grinding and polishing method of manual experience is time-consuming and the output is low,CNC machine tool takes a long process-changing time,costs high and occupies a huge area,are difficult to meet the processing requirements of current aircraft engine blades in China.In order to meet the processing quality and production efficiency of current aircraft engine blades,this paper took aeroengine precision casting blades as research objects,and established a robotic abrasive belt grinding and polishing system that integrated 3D measuring equipment.Focused on the distribution of the machining allowance of precision casting blades for 3D measurement and the processing control of grinding and polishing of flexible abrasive belt and other key technologies to carry out in-depth research.The main research results are as follows:1.According to the current structural characteristics of precision casting blades and the requirements of flexible abrasive belt grinding and polishing processing technology,this paper formulated the grinding and polishing process plan,determined the overall scheme of robotic belt grinding system based on 3D measurement technology,and the communication integration scheme between the host computer and the industrial robot control system and the on-line measurement system,and established a robotic abrasive belt grinding and polishing system that integrated 3D measuring equipment.2.A robot grinding and polishing process path that can be adapted to the characteristics of the profile of the precision casting blades was planned.By comparing the currently used tool trajectory planning method,combining the profile features of the precision casting blades,a purposeful planning of the profile line of the blade profile was performed,the trajectory planning method of the abrasive belt grinding and polishing tool was determined to automatically determine the profile of the blade profile and the optimal contact wheel size subset.3.Through the coordinate measuring machine,the measured model data of the precision casting blade was obtained,and the reverse reconstruction of the measured model was realized.At the same time,the theoretical model was pre-processed and the tool contact coordinates were calculated.With the goal of uniforming grinding allowance,the position deviation of the measured model coordinate system was calculated,and a distribution model of allowance was established.4.Research on the control method of flexible abrasive belt grinding and polishing.Based on the distribution model of allowance of the blade contact of the precision casting blade,the design of the floating pressure grinding head was completed.Taking into account the influence of grinding process parameters,a polishing material removal model was established for the precision casting blade,according to Elastic contact theory,the corresponding grinding pressure at each contact point was calculated.5.Based on the Open CASCADE geometry modeling software platform,a set of 3D measurement-based precision casting blade robotic abrasive belt grinding system software was developed by using the C++ programming language.The 3D geometric model of the robotic grinding center was established on the UG8.5 software platform,and the robot off-line processing program was imported under the VERICUT simulation software platform to verify its correctness.6.Using the precision casting blades as a processing objects,a robotic abrasive belt grinding system was used to carry out a grinding and polishing experiment,and the effects before and after the grinding and polishing were compared and analyzed to verify the feasibility and reliability of the robotic abrasive belt grinding system based on 3D measurement.