Research On The Technology Of The In Situ Auto Measurement Of The Aero-engine Blisk

The blisk has taken the place of traditional bladed disk to be a significant part of foreign advanced fighter aviation engines,whereas domestic research on blisk has not been invested a lot of human and material resources until the “Twelfth Five Year Plan”.Detection of the machining precision of the blisk is an effective means to improve the overall quality of the blisk;it's an urgent issue of improving the machining quality,yield and reducing production costs by detecting the blisk in site processing in a high efficiency and high precision way and feeding the detection results back to the machine for reprocessing.Aiming at the practical applications of blisk machined in specific environment,this dissertation provides a systematical and extensive research on the subject of the in site automatic measurement techniques of the machining blisk.The main contents and creative ideas are as follows:1.According to the requirements of the restrict measurement tasks and limited by the narrow on-site space,a cantilevered coordinate measuring machine(CCMM)had been designed and developed in the use of linear guides on the unlimited spatial direction and cantilevered structure on the space restricted direction,which combined the advantages of the articulated arm and the traditional orthogonal coordinate measuring machine.The new type of dynamic scanning REVO system was applied in the new five-axis coordinate measuring system,and the measurement demand in the harsh environment was achieved.2.The REVO 5-axis measuring system was analyzed and the mathematical model of REVO head was established,by which the coordinates of measured points could be reconstructed from the few data returned from controller,and then the REVO 5-axis measuring system could be applied in non-orthogonal CMMs.The detecting vector of REVO applied in non-orthogonal CMM was corrected,the problem of both the incorrect detecting posture and the probable collision was solved,and the measurement accuracy was increased at the same time.3.In view of the designed structure of the CCMM,the machine model of the CCMM was proposed and established,the transfer coefficients of the coordinate measuring uncertainty affected by the original error and the synthetic relationship of every geometrical error were derived.Based on the pseudo-rigid model,7 separate coordinate systems including the REVO A-axis coordinate system,the REVO B-axis coordinate system,the rotating arm coordinate system,the vertical moving coordinate system,the horizontal moving coordinate system,the working table coordinate system and the rotary table coordinate system were set up.And the relationship between every coordinate system was analyzed,which laid the theoretical foundation for the error compensation of the CCMM.4.Pointing at the error item of CCMM,a set of error calibration techniques were put forward,including the calibration of the probe length of REVO and the zero position of A-axis,the calibration of the zero position of B-axis,the calibration of the offset between A-axis and B-axis,the calibration of the zero position and length of the rotary arm,the calibration of the squareness between the vertical axis and the horizontal axis,the calibration of the parallelism between the vertical axis and the rotatory axis,and the calibration of the parallelism between the B-axis and the rotatory axis.A new approach to the indexing error calibration of machine turntable at any position was presented.And the high accuracy calibration of the calibrated parameter was achieved by minimizing the effect of the other error items.