Research On Measurement Principle And Technology Of Blade Surface

With the rapid development of aviation, shipbuilding, motor vehicle and moldindustry, the requirement of the processing and size measurement of the machine parts withfree-form surface becomes higher and higher. As a kind of typical complex camber,geometrical errors of it have great influence on secondary flow loss. It is one of the reasonswhy measurement of blade surface is in the limelight. The blades surfaces have Complexmodeling and need numerous describe parameters. They contours differ from bottom to topat each section，so the surfaces inspection is very difficult. In that case, detecting blade’ssurface is time and force consuming. Based on the new measuring method of blade’ssurface and the characteristics of it, laser measuring instrument is developed to examinethe vane of engine presser in this paper, which is high accurate and efficient.First, the data measured though measuring machine is processed and the pattern forchecking points on the free-form curve has been realized. Then several kinds’methods forcomputer interpolation have been introduced. By fitting analysis of spline interpolationwith discrete set by Matlab, the curve is closer to processing curve. Then, by analyzing andcomparing the blade surface measurement at home and aboard, a new inspectionmethod-Coordinate Inspection is introduced in this paper. Based on the new method andthe characteristics of the blade surface, corresponding laser measuring system which hasbeen proved to be feasible has been design. Next, through the analysis of the laser systemerror sources, experiment and calculation, the accuracy of laser measurement system isdetermined 0.01 mm. In order to verify the accuracy of the laser measurement system, thelaser measurement system has measured blade type line after measured by coordinatemeasuring machine. Finally, blade type line has been measured by using the linkagemeasurement method on the measurement equipment which is designed and developedindependently. By comparing the actual measurement data and the theoretical data, bladetype line can be measured by laser measurement system in this paper. Measuring precisionof blade meets the measuring precision requirement of manufacturer and measurement speed improved greatly, which have verified the feasibility of this method and stability andreliability of the measuring equipment.