Research On The Runout And Coaxiality Measurement Technique Of Aero-engine Honeycomb Surface

With the development of technology in aero-engine, the assembly precision aero-engine requires better performance and this needs more rapid and accurate measurement methods, especially in the measurement of aero-engine casing. Honeycomb structure could achieve the gas seal function because of smaller sealing clearance, which makes the honeycomb structure widely used in aero-engine case. The runout of the sealing ring in the honeycomb structure and the coaxiality of many sealing rings need to be measured. So this paper is designed for the measurement of honeycomb structure from the measurement method, the error analysis to the data processing. The main research of this paper follows:Firstly, analyzed the features that the honeycomb structure is composed of sector structures, the honeycomb structure is much thinner and the pore size between regular hexagon structures is big. Then designed the measurement method of honeycomb surface structures with cylindrical probes, telescoping sensors and a turntable with special structure.Secondly, analyzed the obliquity error and sampling angle error in the measurement of the honeycomb structure based on the features that the cylindrical probe could not achieve axial rotation and the features of the profile of the honeycomb structure. Reduced the effect of the error of the obliquity of sensors by adjusting sensors properly and eliminated the sampling angle error with hardware trigger sampling based on FIFO structure instead of upper computer scanning. And analyzed and processed the outliers with the limit breadth filter, the median filter, the 3σ guideline and the robust filtering method.Thirdly, designed the measurement model of the coaxial degree, came up with the method that considering the line of the central point in each of two cross-section as the basis axial line according to the fact that the actual axial line of aero-engine is lined with the central point of the intermediate case and the central point of the turbine.Finally, measured the runout of the single piece honeycomb structure and the eccentricity of the whole circle profile which is composed of pieces of honeycomb structure. The runout of the single piece honeycomb structure is in the range of 150μm to 200μm, which accords with actual values.The repeated measures of the eccentricity of the whole circle profile showed that the maximum difference is 2μm which could make the surface of the honeycomb structure meet the requirement of micrometers.