A Longitudinal Measurement Method for Complex Curved Surface Blades of Integral Blisks

Abstract

A longitudinal measurement method for a blisk complex curved surface blade is characterized by comprising the following steps that firstly, a complex curved surface CAD three-dimensional model is built according to blade profile theoretical section contour data; secondly, longitudinal detection lines are extracted from the leading edge, the trailing edge, the basin and the back of the blade, a three-coordinate measuring machine is adopted for detecting a real object of the blade in a longitudinal detection mode, and data processing is further conducted on a sampling point; finally, processed sampled data are input into the CAD three-dimensional model to be compared and analyzed, and a comprehensive and real blade profile data set is obtained. The longitudinal measurement method for the blisk complex curved surface blade has the advantages that measurement path planning is simple; the real state of a blade profile can be reflected comprehensively; a short probe can be selected, and therefore measurement efficiency can be improved while detection precision is improved.

Description

technical field [0001] The invention relates to the technical field of mechanical processing and detection, in particular to a method for longitudinal measurement of blades with complex curved surfaces of integral blisks. Background technique [0002] With the urgent demand for high-performance indicators of power output equipment such as propellers, blowers, steam turbines, and compressors, parts with various overall structures and complex shapes are widely used. For integral blisks and impeller structural parts, whether the final processing state of the airfoil profile meets the requirements of the design drawings has an extremely significant impact on its performance, or it can be said to directly affect the working performance and use of the equipment. life. In order to improve the performance of the power output equipment, the blades of the integral impeller and the blisk structure parts are mostly non-straight-grained airfoils, and the torsion is large, and the radius...

AI Technical Summary

Problems solved by technology

There are four problems in the detection method of cross-sectional profile points as follows: 1) The rounded corners of the front and rear edges of the blade are generally less than 1 mm, and considering the rigidity of the measuring rod, the diameter of the measuring head is usually 1 to 3 mm. The measurement results are distorted; 2) The blades are twisted and shielded from each other, so that the probe or laser cannot complete the collection of the complete cross-sectional profile at one time, and it is necessary to change the direction multiple times or replace the probe, resulting in increased measurement errors; 3) The cross-sectional profile After the points are collected, whether the area between the two sections meets the requirements is generally based on the subjective judgment of the inspectors, which cannot truly reflect the real situation of the free-form surface; 4) The measurement efficiency is low

At the same time, the error evaluation often uses the distance between the theoretical point of the section profile and the corresponding measured point as the error value, but the actual measurement cannot guarantee that the measured data point coincides with the theoretical point provided by the three-dimensional surface, so it cannot truly reflect the state of the profile

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