A design method of airfoil allowance for curved blade forgings

Abstract

The invention provides a method for designing a blade body margin of an over-bent blade forge piece. The method comprises the following steps: drawing a three-dimensional model of a part blade body; executing an offset command according to machining margin to obtain a three-dimensional model of the part blade body with the margin increased; extracting section lines of the part and the forge piece according to a sectional distance on a part drawing; importing the section lines in two-dimensional drawing software; drawing two continuous inscribed circles on the exhaust edge of the section line of the part, and drawing an extension line of a connecting line of circle centers; drawing a normal of the extension line on a cross point of the extension line and the section line of the part; offsetting both sides of the extension line to obtain two symmetrical first offset lines, wherein the offset is a half of the thickness of a deckle edge of the exhaust edge of the section line at an over-bent site; offsetting a single side of the normal to obtain a second offset line, wherein the offset is the margin of the exhaust edge at the over-bent site, and the cross points of the first offset lines and the second offset line are respectively marked as first and second edge control points; moving two outer end points of the section line of the forge piece to the first and second edge control points; and inquiring all control points of the section line of the forge piece, and importing the same into a three-dimensional drawing software to generate a three-dimensional model of the blade body of the forge piece.

Description

technical field [0001] The invention belongs to the technical field of manufacturing aeroengine blades, and in particular relates to a method for designing blade body margins of curved blade forgings. Background technique [0002] With the continuous improvement of the thrust requirements of aero-engines, the blade shape of aero-engines also tends to be complicated. Taking a curved blade as an example, the line connecting the centers of gravity of each section of the curved blade body is close to the curve of the tip part. The curvature increases sharply, and the bending angle of the curved blade airfoil can reach up to 60°. If the traditional blade forging airfoil allowance design method is adopted, the following can be obtained: figure 1 For the blade forging shown, the local machining allowance at the bending part of the blade forging will be less than 30%, and the overall machining allowance distribution of the bending blade forging blade body is also very uneven, which ...

AI Technical Summary

Problems solved by technology

[0002] With the continuous improvement of the thrust requirements of aero-engines, the blade shape of aero-engines also tends to be complicated. Taking a curved blade as an example, the line connecting the centers of gravity of each section of the curved blade body is close to the curve of the tip part. The curvature increases sharply, and the bending angle of the curved blade airfoil can reach up to 60°. If the traditional blade forging airfoil allowance design method is adopted, the following can be obtained: figure 1 For the blade forging shown, the local machining allowance at the bending part of the blade forging will be less than 30%, and the overall machining allowance distribution of the bending blade forging blade body is also very uneven, which will lead to bending The blade parts are prone to stress deformation after machining, which seriously reduces the product qualification rate of the curved blade parts

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