A Method of Improving the Accuracy of Reverse Engineering of Impeller Parts

Abstract

The invention provides a method for improving reverse engineering accuracy of an impeller part. The method includes: (A), selecting samples, (B), building a coordinate system of the samples; (C), scanning the samples into point cloud data Pa; (D), building a coordinate system on a three-coordinate measuring machine; (E) sequentially comparing parameters of dimension errors, strength and quality of a three-dimensional solid model with three data of the samples, and using the three-dimensional solid model nearest to the samples as the final model; and (F) exporting the three-dimensional solid model selected in the step (E), and exporting two-dimensional drawings. By means of the method, structure and dimension of impeller parts with high accuracy can be obtained under the condition that the samples cannot be damaged, the two-dimensional drawings of the impeller parts can be obtained for manufacturing and processing of products, the impeller profile error can be controlled to be lower than 0.08mm, and the errors of other dimensions can be controlled to be lower than 0.02mm. The impeller manufactured by the method is high in fidelity and can meet the using requirements.

Description

technical field [0001] The invention relates to guidance drawings in the impeller manufacturing industry of compressors and propellers, in particular to a method for improving the reverse engineering precision of impeller parts. Background technique [0002] The impeller is the core component of compressors and propellers, and is widely used in the aerospace field. The profile of the impeller blade is complex, the design, manufacture and test are difficult, and the development cycle is long. The development of the impeller by the inverse method has the advantages of short period and low cost, but the impeller parts have strict requirements on the strength and aerodynamics of the blade shape, resulting in high requirements for the inverse accuracy of the impeller parts. At present, the reverse calculation method of general impeller parts includes two contents: impeller sample digitization and three-dimensional CAD model reconstruction. The traditional method is: [0003] 1...

AI Technical Summary

Problems solved by technology

[0003] 1 Due to cost reasons and time constraints, the traditional method only scans one sample to obtain point cloud data; only one (a group) of blades in the point cloud data is used to build a three-dimensional solid model of impeller parts, and the obtained model has greater randomness. There may be a large error from the original design

[0004] 2 The traditional method of model evaluation uses the error analysis function that comes with the inverse software to compare the point cloud data with the 3D solid model, only considering the error between the point cloud and the 3D solid model, and ignoring the error of the scanned point cloud. Since each blade of the cast impeller is different, only the point cloud data of one blade is used for modeling when modeling, and then all blades are obtained in an array, and the error values ​​of other blades obtained by using the error analysis function that comes with the reverse calculation software Too big

[0005] 3 The traditional method only compares the three-dimensional solid model of the impeller with the geometric dimensions of the sample to evaluate the accuracy of the model