Design and optimization method of correction die for precision small margin blades of aero-engine

Abstract

The present invention discloses a design and optimization method for a precision small-residue blade correction die for an aero-engine. On the basis that the final forging die is qualified, the pre-torsion compensation for the forging rebound deformation of the blade profile of each section of the final forging die is cancelled and a trimming die is designed. The pre-torsion compensation size of the blade profile of each section is reduced to 1 / 2 of the original to form the first version of the correction die, and the forging is heated and pressure-tested. The torsion angle deviation of the size of each section of the forging from the theoretical size after the pressure test and the contour deviation after the torsion angle fitting are measured. According to the torsion angle deviation, the correction die profile is rotated accordingly, and points of equal arc length are taken on a single spline curve of the correction die profile. The point coordinates are output and adjusted according to the contour deviation. After adjustment, a new spline curve is made and smoothed to complete the design of the second version of the correction die. The above steps are repeated until the correction size meets the requirements. The present invention improves the dimensional accuracy of small-residue blade correction parts, eliminates the need for die repair, and improves production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine blade correction molds, and in particular relates to a design and optimization method of an aero-engine precision small-margin blade correction mold. Background Art

[0002] Aircraft engine blade forgings require high dimensional control, especially for precision blades with small machining allowances (small machining allowances here refer to machining allowances of 0.2 to 0.5 mm). Calibration, as the final forging step, plays a key role in forging size. During thermal calibration, forging deformation is minimal, resulting in localized plastic and elastic deformation, making dimensional control challenging.

[0003] At present, the traditional correction die designed based on forging theory is only suitable for large-allowance forgings. When the aforementioned correction die is used to correct precision small-allowance forgings, the plastic deformation and elastic deformation of the forgings will cause the local allowance of the forgings to be small or even no allowance. Summary of the Invention

[0004] The present invention aims to provide a design and optimization method for a correction die for precision small-allowance blades of an aero-engine, so as to solve the influence of local plastic deformation and elastic deformation on the size when correcting precision small-allowance blade forgings and accurately control the size of the forgings.

[0005] The technical solutions of the present invention are as follows:

[0006] The design and optimization method of the precision small margin blade correction mold of an aero-engine includes the following steps:

[0007] Step 1: Design the trimming die based on the qualified final forging die, which specifically includes the following steps:

[0008] Step 1.1, cancel the pre-torsion compensation of forging springback deformation of each section of the blade profile in the final forging die;

[0009] Step 1.2, using Boolean operations to make a trimming die based on the final forging die, and using the trimming die to trim the final forging;

[0010] Step 2: On the basis of the final forging die being qualified, the pre-torsion compensation of the blade profile of each section is reduced to 1 / 2 of the original value to form the first version correction die, and the first version correction die is used to heat the forging and perform correction pressure testing;

[0011] Step 3: measuring the torsion angle deviation Δα between the dimensions of each cross section of the forging after the press test and the theoretical dimensions, and the profile deviations Δb1, Δb2, etc. after torsion angle fitting;

[0012] Step 4: According to the torsion angle deviation, the mold profile is rotated by -Δα, and the center of rotation is the center of mass of the theoretical profile;

[0013] Step 5: Sequentially select multiple points on a single spline curve of the cross-section profile of the correction mold, output the point coordinates, and adjust the Y values ​​of the corresponding point coordinates by -Δb1, -Δb2, etc. according to the profile deviations Δb1, Δb2, etc. After adjustment, a new spline curve is drawn, and then the curve is smoothed to form the second version of the correction mold;

[0014] Step 6: Repeat steps 3, 4, and 5 until the correction size meets the requirements.

[0015] It should be pointed out that the meaning of the aforementioned steps 1 and 2 on the basis of qualified final forging dies is that the final forging dies do not need to be polished or repaired when adjusting the dies, and qualified forgings can be produced by simply adding or removing gaskets up and down, left and right, and front and back.

[0016] It should be pointed out that the use of Boolean operations in the aforementioned step 1.2 to make a trimming die based on the final forging die means: in the modeling software (such as UG), the entity merging, trimming and other operation instructions are performed on the mold 3D model (shape).

[0017] It should be noted that the contour deviation in the aforementioned step 3 refers to the coordinate difference in the Y-axis direction by default.

[0018] Furthermore, in step 1, the trimming die is designed using UG software.

[0019] Furthermore, in step 2, the UG software is used to reduce the pre-torsion compensation size of the blade profile of each section to 1 / 2 of the original value to form a first version of the correction mold.

[0020] Furthermore, in step 3, the torsion angle deviation Δα between the dimensions of each cross section of the forging after the press test and the theoretical dimensions and the contour deviations Δb1, Δb2, ... after torsion angle fitting are measured using three-coordinate measurement.

[0021] Furthermore, in step 5, multiple points are taken on a single spline curve of the cross-section profile of the correction mold in an order of equal arc length.

[0022] As an option, the number of points taken in a sequence of equal arc lengths on a single spline curve of the cross-sectional profile of the correction mold is greater than or equal to 100.

[0023] The existing correction die design method is not suitable for the correction of precision small-allowance blade forgings, and the correction size deviation is large.

[0024] Compared with the existing correction die design method, the present invention fully considers the local plastic deformation and elastic deformation during the correction process, compensates for the deformation during die design and optimization, improves the dimensional accuracy of the correction part, and can be used for the correction of precision small-allowance blade forgings.

[0025] In addition, since the present invention designs the correction mold on the basis of the qualified final forging mold, when iterating the mold version, it is only necessary to adjust the upper and lower, left and right, front and back gaskets of the mold when adjusting the mold, and no mold surface trimming is involved. Therefore, the correction mold designed and optimized by the present invention does not need to be trimmed when producing products on site, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of three-coordinate measurement of blade forgings in the present invention;

[0027] Figure 2 Schematic diagram of the optimization of the pre-torsion angle of the correction mode in the present invention;

[0028] Figure 3 Schematic diagram of the correction die profile optimization in the present invention;

[0029] Figure 4 Schematic diagram of the trimming die in the present invention;

[0030] Figure 5 Schematic diagram of the correction mode in the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0032] like Figures 1 to 5 As shown in FIG, the design and optimization method of the aircraft engine precision small margin blade correction mold adopted by the present invention includes the following steps:

[0033] Step 1: On the basis of the qualified final forging die, use UG software to design the trimming die. The trimming die design steps are as follows:

[0034] Step 1.1: Cancel the pre-torsion compensation for the forging springback deformation of the blade profile of each section in the final forging die;

[0035] Step 1.2: Use Boolean operations to make a trimming die based on the final forging die;

[0036] like Figure 4 , is a trimming die designed by the above steps, the trimming die designed in this way has small deformation during hot trimming and is convenient for correction, and then, the trimming die is used to trim the final forging;

[0037] Step 2: On the basis of the final forging die being qualified, use UG software to reduce the pre-torsion compensation size of each section of the blade body line to 1 / 2 of the original to form the first version of the correction die, such as Figure 5As shown;

[0038] Step 3: Adoption Figure 5 The first version of the correction die shown is used to heat the forging and perform correction pressure testing. The three-coordinate measurement is used to measure the torsion angle deviation Δα of the dimensions of each section of the forging after the pressure test and the theoretical dimensions, as well as the contour deviation Δb1, Δb2 after torsion angle fitting, as shown in the figure. Figure 1 As shown;

[0039] Step 4: According to the torsion angle deviation, the mold profile is rotated by -Δα, and the center of rotation is the centroid of the theoretical profile, such as Figure 2 As shown;

[0040] Step 5: Select 100 points of equal arc length on the single spline curve of the mold cross-section profile, output the point coordinates, and adjust the Y value of the corresponding point coordinates by -Δb1, -Δb2, etc. according to the contour deviation Δb1, Δb2, etc. After adjustment, make a new spline curve, and then smooth the curve, such as Figure 3 As shown, the design of the second version of the correction mold is completed.

[0041] Step 5: Repeat steps (3), (4), and (5) until the correction size meets the requirements.

[0042] Any matters not described in detail in the present specification are prior art known to those skilled in the art. Although the above description of the present invention is based on illustrative embodiments to facilitate understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the specific embodiments. As long as various modifications are within the spirit and scope of the present invention as defined and determined by the appended claims, such modifications will be obvious to those skilled in the art, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. Design and optimization method of aero-engine precision small margin blade correction mold, characterized by: The following steps are included: Step 1: Design the trimming die based on the qualified final forging die, which specifically includes the following steps: Step 1.1, cancel the pre-torsion compensation of forging springback deformation of each section of the blade profile in the final forging die; Step 1.2, using Boolean operations to make a trimming die based on the final forging die, and using the trimming die to trim the final forging; Step 2: On the basis of the final forging die being qualified, the pre-torsion compensation of the blade profile of each section is reduced to 1 / 2 of the original value to form the first version correction die, and the first version correction die is used to heat the forging and perform correction pressure testing; Step 3: measuring the torsion angle deviation Δα between the dimensions of each cross section of the forging after the press test and the theoretical dimensions, and the profile deviations Δb1, Δb2, etc. after torsion angle fitting; Step 4: According to the torsion angle deviation, the mold profile is rotated by -Δα, and the center of rotation is the center of mass of the theoretical profile; Step 5: Sequentially select multiple points on a single spline curve of the cross-section profile of the correction mold, output the point coordinates, and adjust the Y values ​​of the corresponding point coordinates by -Δb1, -Δb2, etc. according to the profile deviations Δb1, Δb2, etc. After adjustment, a new spline curve is drawn, and then the curve is smoothed to form the second version of the correction mold; Step 6: Repeat steps 3, 4, and 5 until the correction size meets the requirements.

2. The design and optimization method for the aircraft engine precision small margin blade correction mold according to claim 1 is characterized by: In the step 1, the trimming die is designed using UG software.

3. The design and optimization method of the aircraft engine precision small margin blade correction mold according to claim 1 is characterized by: In step 2, UG software is used to reduce the pre-torsion compensation size of the blade profile of each section to 1 / 2 of the original size to form a first version of the correction mold.

4. The design and optimization method for the aircraft engine precision small margin blade correction mold according to claim 1 is characterized by: In step 3, three-coordinate measurement is used to measure the torsion angle deviation Δα between the dimensions of each cross section of the forging after the press test and the theoretical dimensions, as well as the contour deviations Δb1, Δb2, ... after torsion angle fitting.

5. The design and optimization method of the aircraft engine precision small margin blade correction mold according to claim 1 is characterized by: In step 5, a plurality of points are taken on a single spline curve of the cross-section profile of the correction mold in a sequence of equal arc lengths.

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