A method for precise control of airway dimensions of double-crown precision forged blades

Abstract

The present invention discloses a method for accurately controlling the airway size of a double-crown precision forged blade, comprising the following steps: establishing a double-crown precision forged blade model and performing process size control on the double-crown precision forged blade; performing bending measurement on the double-crown precision forged blade after forging; performing thickness detection on the blade body of the double-crown precision forged blade after forging; detecting the relative theoretical position of the edge plate and the blade crown of the double-crown precision forged blade after forging; detecting the blade body defect depth of the double-crown precision forged blade after forging; detecting the forging misalignment of the double-crown precision forged blade after forging; determining the rotation angle θ after deformation relative to the blade center based on the bending value and the blade body length of the double-crown precision forged blade; calculating the change value of the tenon and the blade crown caused by the bending based on the bending change value of the double-crown precision forged blade and the rotation angle θ, determining whether the blade is misaligned and the actual value of the design margin of the blade body and the blade crown; and completing accurate control of the airway size of the double-crown precision forged blade.

Description

Technical Field

[0001] The present invention belongs to the field of blade forging, and in particular to a method for precisely controlling the airway dimensions of a double-crown precision forged blade. Background Art

[0002] Blades are key components in aircraft engines. In recent years, many domestic companies and experts have conducted in-depth research on blade precision forging processes and inspection techniques, achieving significant results. Due to the late development of blade precision forging technology in my country, imperfect processes, and outdated equipment, controlling the dimensional control of double-crown precision-forged blades has become a challenge. Blade bending and torsional deformation affect blade airway dimensional measurement and inspection, resulting in a significant gap between my country's precision-forged blade manufacturing technology and advanced international standards. Currently, controlling airway dimensional deformation in double-crown precision-forged blades in China is a major challenge. To ensure the design margin of the shroud inner edge plate, the shroud margin of precision-forged blades is typically 0.20mm to 0.85mm larger than the blade body margin. Bending deformation during the forging process ranges from -0.50mm to 0.65mm, and the shroud margin varies from -0.10mm to 1.00mm. This makes it difficult to remove the shroud margin in subsequent operations, resulting in significant waste of production costs.

[0003] The reasons why the airway size of double-crown precision forged blades is difficult to control include: bending of forged blades, pressure fluctuations of forging equipment, longitudinal and lateral displacement of blades during the forging process, thickness changes and surface quality of blades during the forging process. These problems will affect the final airway size of precision forged double-crown blades. At present, in the invention patent of "A method for precision forging of titanium alloy double-mounting plate stator blades", Shenyang Liming Company discloses a method for top forging and isothermal pre-forging of titanium alloy double-mounting plate stator blades. This method belongs to the blank forming process and only discloses the forging temperature and operation method. It cannot solve the problem of precise control of the deformation of the airway size of precision forged blades. Therefore, there is an urgent need for a control method to solve the change of the airway size of precision forged blades, so as to solve the various problems of airway size change in the production process of double-crown precision forged blades.

[0004] In summary, the existing technology has a problem in controlling the change in airway size and the bending deformation of the blade during the forging process of the double-crown precision forging blade. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a method for precise control of the airway size of double-crown precision forged blades to solve the control problem between the airway size change and the blade bending deformation during the forging process of double-crown precision forged blades, and at the same time solves the control problems caused by the blade crown margin, blade body thickness fluctuation, surface quality state, and blade longitudinal displacement during the blade forging process.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for accurately controlling the airway size of a double-crown precision forged blade comprises the following steps:

[0008] Step 1: Establish a double-crown precision forging blade model and perform process dimensional control on the double-crown precision forging blade;

[0009] Step 2, measuring the bending of the double-crown precision forged blade after forging;

[0010] Step 3, performing thickness testing on the blade body of the double-crown precision forged blade after forging;

[0011] Step 4: detecting the relative theoretical position of the edge plate and the blade crown of the double-crown precision forged blade after forging;

[0012] Step 5: detecting the depth of blade defects of the double-crown precision forged blade after forging;

[0013] Step 6, detecting the forging misalignment of the double-crown precision forged blade after forging;

[0014] Step 7: Determine the rotation angle θ relative to the center of the blade after deformation based on the bending value and blade length of the double-crown precision forged blade;

[0015] Step 8: Based on the bending change value of the double-crown precision forged blade in step 2 and the rotation angle θ in step 7, the change value of the tenon and the blade crown due to bending is calculated to determine whether the blade is misaligned and the actual value of the blade body and blade crown design margin;

[0016] Step 9: Use chemical milling process to eliminate the design allowance of the blade body and blade crown of the double-crown precision forging blade; use sanding belt polishing to remove the surface defects of the blade body and blade crown, and complete the precise control of the airway size of the double-crown precision forging blade.

[0017] Preferably, in step 1, a triangular model is established based on the length, edge plate height, and curvature value of the double-crown precision forged blade.

[0018] Preferably, in step 2, during the forging process of the double-crown precision forged blade, spot checks are performed, and a three-coordinate or inductance meter is used to detect the bending of the blade, and the positive and negative bending and size of the crown precision forged blade are measured.

[0019] Preferably, in step 3, the blade body thickness is measured by a three-coordinate measuring instrument or an inductance measuring instrument to find the lowest point of the blade body thickness of the double-crown precision forged blade.

[0020] Preferably, in step 4, the difference between the theoretical positions of the edge plate and the blade crown of the double-crown precision forged blade is detected by a three-coordinate measuring instrument or an inductance measuring instrument.

[0021] Preferably, in step 5, the depth of the blade defects of the double-crown precision forged blade is determined by using a surface defect analyzer or a surface standard.

[0022] Preferably, in step 6, the longitudinal fluctuation value and the lateral offset value of the double-crown precision forged blade are calculated by measuring the edge plate and profile parameters of the double-crown precision forged blade.

[0023] Preferably, in step 7, the rotation angle θ=tan-1(ΔW / (X12+Y12)1 / 2);

[0024] Where: △W is the height change value of the detection point.

[0025] Preferably, in step 9, the bath liquid is heated to a temperature in the range of 35° C. to 55° C. through a chemical milling process, and then the double-crown precision forged blade is placed in a drum for chemical milling.

[0026] Preferably, in step 9, a sanding belt with a particle size of no more than 240 mesh is used to polish the surface defects of the blade body and blade crown of the double-crown precision forging blade, and after polishing, the airway size and surface quality requirements of the double-crown blade are met.

[0027] Compared with the prior art, the present invention has the following beneficial technical effects:

[0028] The present invention provides a method for precisely controlling the airway dimensions of double-crown precision-forged blades, which first controls the thickness dimension during the forging process, and secondly controls the surface quality and longitudinal offset of the precision-forged blades. Through reasonable calculations and excluding the influence of the blade's own bending, offset, etc., combined with the depth of the blade surface defects that need to be removed during the forging process, it is finally determined whether the blade airway dimensions are appropriate. When the double-crown precision-forged blades have large bending, surface defects, and longitudinal offsets due to equipment and production condition limitations, the forging mold cavity can be designed and the airway dimension control process can be precisely controlled using the method of the present invention, thereby improving the delivery qualification rate of such products. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the airway size control point of the high-pressure 1st stage stator double crown blade;

[0030] Figure 2 This is the bending measurement diagram of the double crown blades of the high-pressure 1st stage stator;

[0031] Figure 3 This is the air duct deformation when the first-stage stator blades of a certain machine are bent;

[0032] Figure 4 Modeling diagram of the blade bending airway size triangle;

[0033] Figure 5 This is the coordinate change diagram of the airway detection point of the blade bending deformation;

[0034] In the picture: 1 is the tenon; 2 is the back of the leaf; 3 is the crown of the leaf; 4 is the leaf basin. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0036] A method for accurately controlling the airway dimensions of a double-crown precision forged blade according to the present invention comprises the following steps:

[0037] Step 1: Create a double-crown precision forging blade model: A triangular model is created based on the blade's length, lip height, and curvature. Based on this model, the primary focus is on controlling the thickness of the double-crown precision forged blade during the forging process, and the secondary focus is on controlling the surface quality and longitudinal offset of the blade during the double-crown precision forging process.

[0038] Step 2, blade bending measurement: random inspection is carried out during the forging process of double crown precision forging blades. The bending of the blades is detected using a three-coordinate or inductance meter to measure the positive and negative bending and size of the blades.

[0039] Step 3: Blade thickness detection: Use a three-coordinate measuring instrument or an inductance meter to detect the blade thickness and find the lowest point of the blade thickness.

[0040] Step 4: Detecting the relative theoretical positions of the blade and the canopy: Detect the difference between the relative theoretical positions of the blade and the canopy using a three-coordinate measuring instrument or an inductance meter.

[0041] Step 5, surface quality control: Determine the depth of the blade defects by using a surface defect analyzer or surface standards.

[0042] Step 6: Blade forging offset control: Calculate the longitudinal and transverse offset values ​​of the blade by measuring the parameters of the precision forged blade edge plate and profile.

[0043] Step 7: Controlling the airway dimensions of double-crown precision-forged blades. To achieve the precise airway dimensions of double-crown precision-forged blades, reasonable calculations must be used to eliminate the effects of blade bending and misalignment. This is combined with the depth of surface defects that need to be removed during the forging process to ultimately determine whether the blade airway dimensions are appropriate.

[0044] Step 8: When the bending value of the blade is much smaller than the length of the blade, that is, the rotation angle θ of the blade detection point relative to the center of the blade before and after the change is very small, then △V4=X2-X1 is the change value of the relative bending of the tenon point V4.

[0045] X2=COSθ(X1+Y1tanθ); the airway size value at point V4 after the bending change is generated;

[0046] Y2=COSθ(Y1-X1tanθ); the height value of point V4 after the bending change is generated;

[0047] △W=Y2-Y1; the height change of point V4 before and after the bending change;

[0048] △W=h; when measuring the blade bending, the two ends are aligned with the reference, and the bending of the middle part of the blade is exactly equal to the height change of V4;

[0049] θ = tan-1(△W / (X12+Y12)1 / 2); given the coordinates of point V4 and the height change, the rotation angle θ can be determined;

[0050] △4=X2-X1;

[0051] =COSθ*(X1+Y1tanθ)-X1;

[0052] Step 9, forging process. The blade body thickness is T, and the blade crown allowance design size of the double crown precision forging blade final forging die is as follows;

[0053] Leaf crown margin = T + longitudinal fluctuation + 2 × amount of light on the surface.

[0054] Step 10: Use chemical milling technology to eliminate the design margins of the blade body and blade crown.

[0055] Step 11: Use sanding belt polishing to remove surface defects of the blade body and crown. After polishing, the airway size requirements of the double crown blade can be met.

[0056] The present invention provides a method for precisely controlling the airway dimensions of a double-crown precision-forged blade. First, the thickness dimension of the forging process is controlled based on the double-crown precision-forged blade model, and secondly, the surface quality and longitudinal offset of the precision-forged blade are controlled. After completing the forging control of the double-crown precision-forged blade, the double-crown precision-forged blade after forging is subjected to corresponding dimensional inspection. By using a reasonable calculation method to eliminate the influence of the blade's own bending, offset, etc., and combining the depth of the blade surface defects that need to be removed during the forging process, it is finally determined whether the blade airway dimensions are appropriate. When the double-crown precision-forged blade has large bending, surface defects, and longitudinal offset due to limitations in equipment and production conditions, the forging mold cavity can be designed and the airway dimension control process can be precisely controlled by the above-mentioned method, thereby improving the delivery qualification rate of such products.

[0057] Example

[0058] Taking the air passage size control of the blade crown of a high-pressure first-stage stator blade of a certain type of engine as an example, a method for accurately controlling the air passage size of a double-crown precision forged blade of the present invention includes the following steps:

[0059] (1) According to the size of the high-pressure first-stage stator blade of a certain machine in actual production, the total length of the airway size is 82.00mm, the height of the V4 detection point is 16.75mm, and the height of the V7 detection point is 11.75mm. Establish a model to determine: According to the length of the blade, the height of the V-point monitoring point, and the bending value of the blade, a triangular model is established to obtain the input parameters, X1 = 82.00 ÷ 2; Y1 = 16.75. Figure 1As shown, the double-crown precision forged blade includes a tenon 1, a blade back 2, a blade crown 3 and a blade basin 4. Figure 1 Among them, V1 is the blade basin tenon detection point, V4 is the blade back tenon detection point, V7 is the blade back leaf crown detection point, and V10 is the blade basin leaf crown detection point. In this embodiment, four detection points are used, and multiple monitoring points can also be designed.

[0060] (2) Blade bending measurement: During the double crown precision forging process, spot check the blade bending by using a three-coordinate or inductance meter. Measure the blade bending +0.30mm, such as Figure 2 shown.

[0061] (3) Blade thickness detection: Use a three-dimensional coordinate measuring instrument or an inductance meter to detect the blade thickness and find the lowest point of the blade thickness. The thinnest point of the blade is measured to be 0.40 mm.

[0062] (4) Detection of the relative theoretical position of the edge plate and the blade crown: Use a three-coordinate or inductance meter to detect the difference in the relative theoretical position of the edge plate and the blade crown. The measurement shows that the difference between the V4 point and the blade crown V7 point is 0.22mm and 0.55mm, respectively. Figure 3 As shown, V1 is the detection point of the blade basin before deformation, V1' is the detection point of the blade basin after deformation, △1 ​​is the longitudinal change value of the detection point before and after deformation, V4 is the detection point of the blade basin before deformation, V4' is the detection point of the blade basin after deformation, and △4 is the longitudinal change value of the detection point before and after deformation.

[0063] (5) Surface quality control: The depth of blade defects is determined by using a surface quality analyzer or surface standards. After testing the surface quality of the blade, the maximum depth of the blade defect is 0.05mm.

[0064] (6) Blade forging offset control: By measuring the parameters of the precision forged blade edge plate and profile, the longitudinal and transverse offset values ​​of the blade are calculated. After testing, the longitudinal fluctuation of the blade is 0.10mm and the transverse offset of the blade is 0.03mm.

[0065] (7) When the bending value of the blade is much smaller than the length of the blade, that is, when the rotation angle θ of the blade detection point relative to the center of the blade before and after the change is very small, then △V4=X2-X1 is the change in the relative height of the tenon point V4, which is equal to the bending value of the blade.

[0066] (8) Calculation of airway size control for double-crown precision forged blades. In order to obtain the precise airway size of double-crown precision forged blades, it is necessary to use a reasonable calculation method and eliminate the influence of the blade's own bending, misalignment, etc., combined with the depth of the blade surface defects that need to be removed during the forging process, to finally determine whether the blade airway size is appropriate.

[0067] △W=Y2-Y1; the height change of point V4 before and after the bending change;

[0068] △W=h; when measuring the blade bending, the two ends are aligned with the reference, and the bending of the middle part of the blade is exactly equal to the height change of V4;

[0069] θ = tan-1(△W / (X12+Y12)1 / 2); given the coordinates of point V4 and the height change, the rotation angle θ can be determined; X12 and Y12 are the calculated values ​​of points X1 and Y1.

[0070] θ=tan-1(0.30 / (41.002+16.752)1 / 2);

[0071] θ = 0.388°;

[0072] X2=COSθ(X1+Y1tanθ); the airway size value at point V4 after the bending change is generated;

[0073] X2=COS0.388*(41+16.75*tan0.388);

[0074] X2=41.112;

[0075] △4=X2-X1=41.112-41.00=0.112(mm);

[0076] Therefore, it can be determined that the V4 point detection value of this forged blade is 0.112mm larger due to the bending effect, and the accurate value should be V4 = 0.22-0.112 = 0.108mm; by the same logic, the measurement error of V7 point can be determined as: △7 = X2-X1 = 41.078 -41.00 = 0.078 (mm), and the accurate value should be V7 = 0.55-0.078 = 0.472 (mm). Figure 4 and Figure 5 As shown, V1 is the blade basin tenon detection point, V4 is the blade back tenon detection point, V7 is the blade back and leaf crown detection point, and V10 is the blade basin and leaf crown detection point; (X1, Y1) is the original coordinate value of point V4, (X2, Y2) is the initial coordinate value of point V4 after deformation, θ is the triangle rotation angle, and △4 is the X movement position of point V4 before and after deformation.

[0077] (9) The blade thickness of the forging process is 0.40 mm, and the blade crown allowance design dimensions of the double crown precision forging blade final forging die are as follows;

[0078] Leaf crown margin = T + longitudinal fluctuation + 2 × amount of light on the surface;

[0079] Leaf crown margin = 0.40 + 0.10 + 2 × 0.05 = 0.60 (mm);

[0080] (10) Chemical milling is used to eliminate the design margin of the blade body and crown. Through the chemical milling process, the tank liquid is heated to a range of 35℃ to 55℃, and then the blade is placed in the drum for chemical milling, with the chemical milling depth of 0.40mm.

[0081] (11) Use a sanding belt with a particle size of no more than 240 mesh to polish the surface defects of the blade body and crown. After polishing, the airway size and surface quality requirements of the double crown blade can be met.

Claims

1. A method for accurately controlling the airway size of a double-crown precision forged blade, characterized in that: The following steps are included: Step 1: Establish a double-crown precision forging blade model and perform process dimensional control on the double-crown precision forging blade; Step 2, measuring the bending of the double-crown precision forged blade after forging; Step 3, performing thickness testing on the blade body of the double-crown precision forged blade after forging; Step 4: detecting the relative theoretical position of the edge plate and the blade crown of the double-crown precision forged blade after forging; Step 5: detecting the depth of blade defects of the double-crown precision forged blade after forging; Step 6, detecting the forging misalignment of the double-crown precision forged blade after forging; Step 7: Determine the rotation angle θ relative to the center of the blade after deformation based on the bending value and blade length of the double-crown precision forged blade; Step 8, based on the bending change value of the double crown precision forged blade in step 2 and the rotation angle θ in step 7, calculate the change value of the tenon (1) and the blade crown (3) caused by bending, determine whether the blade is misaligned and the actual value of the blade body and blade crown design margin; Step 9: Use chemical milling to eliminate the design allowances of the blade body and blade crown of the double-crown precision forging blade; use abrasive belt polishing to remove surface defects of the blade body and blade crown, and complete the precise control of the airway size of the double-crown precision forging blade; In step 1, a triangular model is established based on the length, edge plate height and curvature value of the double-crown precision forged blade; In step 2, during the forging process of the double crown precision forged blade, a random inspection is performed, and the bending of the blade is detected using a three-coordinate measuring instrument or an inductance measuring instrument, and the positive and negative bending and size of the crown precision forged blade are measured; In step 3, the blade thickness is measured by a three-coordinate measuring instrument or an inductance measuring instrument to find the lowest point of the blade thickness of the double-crown precision forged blade; In step 4, the difference between the theoretical positions of the edge plate and the blade crown of the double-crown precision forged blade is detected by a three-coordinate measuring instrument or an inductance measuring instrument; In step 5, the depth of the blade defects of the double-crown precision forged blade is determined by using a surface defect analyzer or a surface standard; In step 6, the longitudinal fluctuation value and the lateral offset value of the double-crown precision forged blade are calculated by measuring the edge plate and profile parameters of the double-crown precision forged blade; In step 7, the rotation angle θ = tan-1 (△W / (X12+Y12)1 / 2); Where: △W is the height change value of the detection point; X12 and Y12 are the calculated values ​​of points X1 and Y1, where (X1, Y1) are the original coordinate values ​​of point V4, and V4 is the blade back tenon detection point.

2. The method for accurately controlling the airway size of a double-crown precision forged blade according to claim 1, characterized in that: In step 9, the bath liquid is heated to a temperature in the range of 35° C. to 55° C. through a chemical milling process, and then the double-crown precision forged blade is placed in a drum for chemical milling.

3. The method for accurately controlling the airway size of a double-crown precision forged blade according to claim 1, characterized in that: In step 9, a sanding belt with a particle size of no more than 240 mesh is used to polish the surface defects of the blade body and blade crown of the double-crown precision forging blade, and after polishing, the airway size and surface quality requirements of the double-crown blade are met.

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