Blade preforming die and design method

Abstract

The application discloses a kind of pre-forging forming die of blade and design method, comprising the following steps, according to the coordinate parameter of M blade profile sections of final forging forming die, area and the deformation reduction of final forging forming, the coordinate parameter of blade body section of pre-forging forming die is calculated;The coordinate parameter of blade profile section of pre-forging forming die calculated is imported into three-dimensional modeling software, and the shape of blade body part of pre-forming piece is generated;According to the parameter of tenon and process chuck of final forging forming die blade body, the parameter of tenon and process chuck of both ends of blade body of pre-forming piece is calculated;With the center line of blade profile of final forging forming die as parting line, the parting surface of pre-forging forming die is constructed, and pre-forging forming die is designed according to parting surface.Pre-forging forming die does not need to design flash groove for accommodating excess metal, metal material is gradually deformed "on demand" distribution, pre-forging piece does not need to be trimmed, both will not cause raw material waste and also will not cause blade deformation.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular, to a method for designing a pre-forging die for a blade. Furthermore, this invention also relates to a pre-forging die for a blade obtained using the aforementioned method for designing a pre-forging die for a blade. Background Technology

[0002] Blades are one of the most important components in aero engines. Compressor blades, stator blades, rectifier blades, and guide blades in front of the turbine of an aero engine are generally made into blanks by forging and then precision machining.

[0003] In existing blade casting methods, the final forging die has a flash groove around the blade profile. The flash groove is mainly used to accommodate excess metal, such as... Figure 1 As shown, the pre-forging die is simply obtained by increasing the blade thickness and tenon size according to the final forging shape, without precise distribution of metal material in each part. Therefore, current pre-forging dies are equipped with flash grooves along the blade contour to accommodate excess metal. After the blade is pre-forged, this excess flash metal also needs to be removed, resulting in material waste. In addition, removing flash may cause blade surface deformation, requiring an additional correction process to compensate. Summary of the Invention

[0004] This invention provides a pre-forging die and design method for blades to solve the technical problems of uneven metal distribution, excessive flash, rapid local wear of the die, and low material utilization rate in existing pre-forging dies during forming.

[0005] According to one aspect of the present invention, a method for designing a pre-forging die for a blade is provided, comprising the following steps:

[0006] S2001: Calculate the coordinate parameters of the blade section of the pre-forging die based on the coordinate parameters and area of ​​the blade section of the final forging die and the deformation reduction of the final forging.

[0007] S2002: Import the coordinate parameters of the blade section of the pre-forging die calculated in step S2001 into the 3D modeling software to generate the shape of the blade body of the pre-forging part.

[0008] S2003: Calculate the dimensional parameters of the tenons and process clamps at both ends of the blade of the pre-forged part based on the dimensional parameters of the tenons and process clamps at both ends of the blade of the final forging die.

[0009] S2004: Using the center lines of the blades of the first to Mth blade sections of the final forging as parting lines, construct the parting surface of the pre-forging;

[0010] S2005: Expand the parting surface of the pre-forging part in all directions to obtain the parting surface of the pre-forging forming mold, and construct a module. The module is divided into the pre-forging forming upper mold and the pre-forging forming lower mold by the parting surface of the pre-forging forming mold.

[0011] S2006: Perform Boolean subtraction between the upper and lower pre-forging dies and the pre-forging solid to obtain a pre-forging die with a cavity.

[0012] Further, step S2001 specifically includes the following steps:

[0013] Given the coordinate point parameters X'' of the blade profile of the final forging die: X'' = {(x0'', y0'', z0''), (x1'', y1'', z1''), (x2'', y2'', z2'') ... (x i '', y i '', z i '')…. (x N '', y N '', z N '')},

[0014] The coordinate parameters of the blade profile of the pre-forging die are defined as X'''={(x0''', y0''', z0'''), (x1''', y1''', z1'''), (x2''', y2''', z2''')...(x i ''',y i ''', z i ''')…. (x N ''',y N ''', z N ''')} ,

[0015] The blade profile coordinate parameters of the pre-forging die can be calculated using the following algorithm:

[0016] make

[0017]

[0018] but

[0019]

[0020] In the formula, δ is the deformation reduction of the final forging, and the value of δ is not less than the minimum critical deformation specified for the blade material. This represents the area of ​​the j-th blade section of the final forging die; Let represent the area of ​​the j-th airfoil section of the pre-forging die; when calculating the airfoil section coordinate parameters of the pre-forging die, first let Calculate the ordinate using Formula 9. The value is then substituted into formula 8 to calculate... Finally, substitute the values ​​into formula 9 to calculate the x-coordinate. The value of .

[0021] Furthermore, in S2003, the cross-section of the tenon of the final forging die blade is circular, and the cross-section of the tenon is elliptical, with the major axis of the ellipse parallel to the forging pressure direction.

[0022] Furthermore, the tenon of the final forging die blade has a circular cross-section with a diameter of d2, and the cross-section of the tenon is elliptical with a major semi-axis of a and a minor semi-axis of b.

[0023] Then the parameters a and b are determined according to the following formula:

[0024] .

[0025] Furthermore, in S2003, the cross-sectional area of ​​the process chuck is equal to the area of ​​the blade end face cross-section to which it is connected.

[0026] Furthermore, step S2004 specifically includes the following steps:

[0027] The coordinate parameters of the blade section of the final forging die calculated by S2001 are X''={(x0'',y0'',z0'')(x1'',y1'',z1'')(x2'',y2'',z2'')…(x i '', y i '', z i '')…. (x N '', y N '', z N The fractal line is calculated using the following algorithm:

[0028] make

[0029]

[0030] In the formula It is a point (x) i '', y i '', z i The first derivative at '') It is a point (x) i '', y i '', z i The second derivative at '') R i Representative point (x) i '', y i '', z i The radius of curvature at '')

[0031] Start the search from point 1, if R is the radius of the inlet and outlet arc of the final forged blade. These are then labeled as flag1, flag2, flag3, and flag4, representing the positions of the tangent points between the inlet and outlet arcs of the blade and the blade base / back curve.

[0032] The coordinate parameters of the blade centerline point are:

[0033]

[0034] Import the calculated parting surface cross-sectional curve data into 3D modeling software to generate the parting surface of the blade part, and then expand it in all directions to obtain the parting surface of the entire mold.

[0035] Furthermore, the material for the final forging is GH2132 alloy.

[0036] Furthermore, the deformation reduction δ of the final forging is greater than 0.2.

[0037] Furthermore, the deformation reduction of the final forging is δ=0.25.

[0038] According to another aspect of the present invention, a pre-forging die for a blade is also provided, which is obtained by the above-described design method for a pre-forging die for a blade, comprising an upper pre-forging die and a lower pre-forging die, wherein the parting surface of the upper pre-forging die and the lower pre-forging die is a curved surface formed by the centerline of the blade section of the final forging.

[0039] The present invention has the following beneficial effects:

[0040] This invention calculates the cavity shape and size of the pre-forging die using the parameters of the final forging die, ensuring that the metal material in the extruded billet is gradually deformed and precisely distributed "on demand" within the pre-forging die. This means there is neither a shortage nor an excess of metal material. Therefore, the pre-forging die designed using this invention does not require flash grooves, and there is no need for trimming after pre-forging, thus preventing material waste. Furthermore, the deformation between the pre-forged part and the final forging obtained using the pre-forging die designed in this invention is precisely designed, meaning that the deformation of each part of the pre-forged part is relatively uniform during final forging. This avoids residual stress caused by uneven deformation, thereby preventing deformation of the forging due to residual stress.

[0041] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0042] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0043] Figure 1 This is a schematic diagram of an existing blade casting method that uses direct die forging from bar stock.

[0044] Figure 2 This is a flowchart of a preferred embodiment of the blade precision forging method of the present invention;

[0045] Figure 3 This is a flowchart of the final forging die design method according to a preferred embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the cross-section of the blade according to a preferred embodiment of the present invention;

[0047] Figure 5 (a) is a schematic diagram of the structure of the M blade cross-sections of a preferred embodiment of the present invention. Figure 5 (b) is a schematic diagram of the angle between the chord of the MM section and the X-axis in a preferred embodiment of the present invention. Figure 5 (c) is a schematic diagram of the angle between the chord of the first section 1-1 and the X-axis in a preferred embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of the blade portion of the final forging according to a preferred embodiment of the present invention;

[0049] Figure 7 This is a schematic diagram of the structure of the final forging according to a preferred embodiment of the present invention;

[0050] Figure 8 This is a schematic diagram of the parting line of the blade section according to a preferred embodiment of the present invention;

[0051] Figure 9 (a) is a schematic diagram of the final forging die according to a preferred embodiment of the present invention. Figure 9 (b) is a structural schematic diagram of the final forging die of a preferred embodiment of the present invention from another perspective. Figure 9 (c) is Figure 9 (b) A sectional view along line AA;

[0052] Figure 10 This is a simulation diagram of the deformation distribution of the pre-forged part during final forging according to a preferred embodiment of the present invention;

[0053] Figure 11 This is a flowchart of a pre-forging forming die design method according to a preferred embodiment of the present invention;

[0054] Figure 12This is a schematic diagram of the blade portion of the pre-forged part according to a preferred embodiment of the present invention;

[0055] Figure 13 This is a schematic diagram of the structure of the pre-forged part according to a preferred embodiment of the present invention;

[0056] Figure 14 This is a schematic diagram of the structure of the pre-forging forming die according to a preferred embodiment of the present invention;

[0057] Figure 15 This is a flowchart of the extrusion die design method according to a preferred embodiment of the present invention;

[0058] Figure 16 This is a schematic diagram illustrating the correlation between the extrusion billet size and the final forging size in a preferred embodiment of the present invention;

[0059] Figure 17 This is a schematic diagram of the extrusion die of a preferred embodiment of the present invention;

[0060] Figure 18 This is a flowchart of the forging process according to a preferred embodiment of the present invention;

[0061] Figure 19 This is a schematic diagram of the blade structure according to a preferred embodiment of the present invention;

[0062] Figure 20 This is a schematic diagram of the blade cross-section parameters plus allowances according to a preferred embodiment of the present invention;

[0063] Figure 21 This is a schematic diagram of the blade portion of the final forging according to a preferred embodiment of the present invention;

[0064] Figure 22 This is a schematic diagram of the parting surface of the final forging die according to a preferred embodiment of the present invention;

[0065] Figure 23 This is a schematic diagram of the parting surface of the final forging according to a preferred embodiment of the present invention;

[0066] Figure 24 This is a schematic diagram of the structure of the pre-forged part according to a preferred embodiment of the present invention;

[0067] Figure 25 This is a schematic diagram of the parting surface of the pre-forging forming die according to a preferred embodiment of the present invention;

[0068] Figure 26 This is a schematic diagram showing the correspondence between the extrusion billet size and the final forging size in a preferred embodiment of the present invention. Detailed Implementation

[0069] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0070] like Figure 2 As shown, the precision forging method for blades in this embodiment includes the following steps:

[0071] S1: Design the final forging die based on the coordinate parameters of the M airfoil sections provided in the blade part design drawing;

[0072] S2: Design the pre-forging die based on the cavity parameters of the final forging die;

[0073] S3: Design the extrusion blanking die based on the cavity parameters of the final forging die and the pre-forging die;

[0074] S4: Using the designed extrusion blanking die, pre-forging die, and final forging die respectively, the bar stock is extruded, pre-forged, and finally forged to obtain the final forging.

[0075] This invention precisely designs based on the parameter characteristics of the blade part design drawing, gradually obtaining the shape and size of the final forging, pre-forging, and extruded billet, and designs corresponding molds for forming processing. This allows the bar stock to gradually deform "as needed" during the forming process, and the metal material to be gradually "distributed as needed." No flash is generated in each forming step, or only a very small amount of flash is generated in the mold gap. Therefore, it can avoid the adverse effects of direct forging of bar stock, and the blade mold life and blade dimensional stability are improved simultaneously. The utilization rate of metal raw materials can reach more than 80%.

[0076] like Figure 3 As shown, the design method of the final forging die in this embodiment includes the following steps:

[0077] S1001: Based on the airfoil section parameters provided in the blade part design drawing, calculate the airfoil section parameters after adding the allowance using the following algorithm.

[0078] like Figure 4 As shown, the blade section parameters given in the blade part design drawing are generally a closed curve consisting of N data points. Assume the coordinate parameters of the points are represented as X = {(x0, y0, z0), (x1, y1, z1), (x2, y2, z2) ... (x...} i y i , z i (x) N y N , z N The coordinate parameters after uniformly adding the allowance are represented as X'={(x0', y0', z0'), (x1', y1', z1'), (x2', y2', z2')...(x i ',y i ',z i')…. (x N ',y N ',z N ')}.

[0079] For any point (x) on the airfoil curve i y i , z i ), coordinates after adding margin (x) i ',y i ',z i The result can be calculated using the following algorithm:

[0080]

[0081] In the formula

[0082] d represents the allowance left for subsequent chemical milling or machining operations on the final forging; k i Point (x) on the curve i y i , z i The first derivative at () k i Values ​​available (x) i y i , z i The coordinate parameters of two nearby points are approximately calculated as follows:

[0083]

[0084] In Formula 1, the "±" sign depends on the arrangement order of the leaf shape data points and the ki value. When the leaf shape curve is a closed curve formed by clockwise arranged points, and the ki value is a "+" value:

[0085]

[0086] When ki is a "-" value:

[0087]

[0088] When the leaf-shaped curve is a closed curve formed by points arranged counterclockwise, and the ki value is a "+" value:

[0089]

[0090] When ki is a "-" value:

[0091]

[0092] Given data points X = {(x0, y0, z0), (x1, y1, z1), (x2, y2, z2) ... (x i y i , z i (x)N y N , z N Whether the arrangement is clockwise or counterclockwise can be determined using the values ​​obtained from the following algorithm:

[0093] make

[0094]

[0095] S represents the line integral of the airfoil curve within the region enclosed by the airfoil cross-section. If S < 0, then X = {(x0, y0, z0), (x1, y1, z1), (x2, y2, z2) ... (x i y i , z i (x) N y N , z N )} indicates clockwise arrangement; conversely, if S>0, it indicates counterclockwise arrangement.

[0096] S1002: Coordinate Transformation for Equilibrium Angle Calculation

[0097] like Figure 5 As shown, given the parameters of M blade sections for the blade part, and calculating the coordinate parameters of the first to Mth sections after adding the allowance according to S1001, the equilibrium angle of the blade in the final forging die can be approximately equal to the average of the angles between the chords of the (1-1)th and (MM)th sections and the X-axis.

[0098]

[0099] The number of blade sections M provided in the blade part drawing is related to the degree of blade twist and the blade length. That is, the larger the blade twist angle and the more complex the shape, the smaller the spacing between the sections (3~5mm) is generally to ensure the smoothness of the 3D model. In this case, the number of blade sections is also more. For example, if a blade is 100mm long and the spacing between the sections is 5mm, the design drawing will provide 21 blade section parameters.

[0100] The coordinate point parameters of the blade section of the final forging die are defined as X''={(x0'', y0'', z0''), (x1'', y1'', z1''), (x2'', y2'', z2'')...(x i '', y i '', z i '')…. (x N '', y N '', z N '')},

[0101] Then for any point (x) after adding the remainder i ',yi ',z i The coordinate parameters (x, y) of the component in the final forging die can be obtained by transforming it using the following algorithm. i '', y i '', z i ''):

[0102]

[0103] In the formula, α is the linear expansion coefficient of the bar stock at the final forging temperature T, and T is the instantaneous temperature of the bar stock at the end of forging.

[0104] S1003: As Figure 6 As shown, by importing the data of the first to Mth cross sections obtained from S1002 into the 3D modeling design software, the shape of the blade part of the final forging can be designed.

[0105] S1004: As Figure 7 As shown, by adding blade tenons at both ends of the blade body of the final forging, or by adding process chucks according to the positioning requirements of machining, for example, by adding chucks with diameters of d1×L1, d2×L2, and d3×L3 at both ends of the blade body, the three-dimensional model design of the final forging can be completed.

[0106] Let the cross-sectional area of ​​the blade section of any final forging be... ,but:

[0107]

[0108] To facilitate extrusion blanking, the chuck portion of the d3×L3 should have a cross-sectional area equal to the area of ​​the blade end face cross-section of the final forging. That is... Therefore, the dimension d3 can be calculated and determined.

[0109] S1005: Construct the mold parting surface.

[0110] The parting surface of the final forging die can be constructed from a series of parting lines. For any blade section, the parting line can be the blade centerline. The coordinate parameters of the blade section calculated by S1002 are X''={(x0'', y0'', z0''), (x1'', y1'', z1''), (x2'', y2'', z2'')…(x i '', y i '', z i '')…. (x N '', y N '', z N The result is calculated using the following algorithm:

[0111] make

[0112]

[0113] In the formula It is a point (x) i '', y i '', z i The first derivative at '') It is a point (x) i '', y i '', z i The second derivative at '') R i Representative point (x) i '', y i '', z i The radius of curvature at '').

[0114] like Figure 8 As shown, the search starts from the first point. (R is the radius of the inlet and outlet arc of the final forged blade), then its subscripts are labeled as flag1, flag2, flag3, and flag4 respectively. These four labels represent the positions of the tangent points of the inlet and outlet arcs of the blade and the blade base / back curve. The coordinate parameters of the blade centerline point are:

[0115]

[0116] like Figure 9 As shown in (a), the calculated parting surface cross-sectional curve data is imported into 3D modeling software to generate the parting surface of the blade portion of the final forging.

[0117] S1006: Expand the parting surface of the blade part of the final forging obtained in S1005 to the four directions to obtain the parting surface of the final forging forming mold, and construct a module. The module is divided into the final forging forming upper mold and the final forging forming lower mold by the parting surface of the final forging forming mold.

[0118] S1007: Perform Boolean subtraction between the upper and lower final forging dies and the final forging solid to obtain a final forging die with a cavity.

[0119] like Figure 9 (a) Figure 9 (b) and Figure 9 As shown in (c), this embodiment provides a final forging die for a blade, which is obtained by the design method of the final forging die described above. It includes an upper final forging die and a lower final forging die. The parting surface of the upper final forging die and the lower final forging die is a curved surface formed by the center line of the blade section of the final forging.

[0120] Current blade final forging dies typically have a flash groove around the blade profile. This flash groove is primarily used to accommodate excess metal. After blade forging, this excess metal needs to be removed, which not only wastes raw materials but may also cause blade deformation during the trimming process. The final forging die design method provided in this embodiment designs the cavity shape and size based on parameters from the blade part design drawing. Since the final forging shape, pre-forging shape, and extruded billet shape are all obtained through a series of calculations based on the blade part characteristics, the metal material is gradually deformed and distributed "on demand," meaning there is neither a shortage nor an excess. Therefore, the final forging die designed with this invention does not require a flash groove to accommodate excess metal, and the forged part after final forging does not require trimming. This avoids both raw material waste and blade deformation. Figure 10 As shown. Furthermore, the final forging mold groove structure without flash is simpler, which is extremely advantageous for mold manufacturing.

[0121] like Figure 11 As shown, the design method of the pre-forging forming die in this embodiment includes the following steps:

[0122] S2001: Set the blade profile coordinate parameters of the pre-forging die as X'''={(x0''',y0''',z0''',(x1''',y1''',z1''',(x2''',y2''',z2''')…(x i ''',y i ''', z i ''')…. (x N ''',y N ''', z N ''')} , and the coordinate point parameters X'' of the blade profile of the final forging die have been calculated as follows: X''={(x0'',y0'',z0'')(x1'',y1'',z1'')(x2'',y2'',z2'')…(x i '', y i '', z i '')…. (x N '', y N '', z N If the blade profile coordinate parameters of the pre-forging die are calculated using the following algorithm:

[0123] make

[0124]

[0125] but

[0126]

[0127] In the formula, δ is the deformation reduction of the final forging, and the value of δ should not be less than the minimum critical deformation specified for the blade material. This represents the area of ​​the j-th blade section of the final forging die; This represents the area of ​​the j-th airfoil section of the pre-forging die. When calculating the airfoil section coordinate parameters of the pre-forging die, first let... Calculate the ordinate using Formula 9. The value is then substituted into formula 8 to calculate... Finally, substitute the values ​​into Formula 9 to calculate the x-coordinate. The value of .

[0128] S2002: As Figure 12 As shown, the blade section coordinate parameters of the pre-forging die calculated by S2001 are imported into the 3D modeling software to generate the blade part of the pre-forged part.

[0129] S2003: As Figure 13 As shown, the tenons or clamps at both ends of the pre-forging die blade are designed based on the shapes of the tenons or process clamps at both ends of the final forging die blade, d1×L1, d2×L2, and d3×L3.

[0130] The dimensions of the clamps remain unchanged, that is, the clamp dimensions at both ends of the pre-forged part are still d1×L1 and d3×L3; the tenon cross-section is designed as an ellipse, with the major semi-axis of the ellipse being a and the minor semi-axis being b. The parameters a and b are determined according to the following formula:

[0131]

[0132] The major axis of the ellipse is parallel to the direction of the forging pressure.

[0133] S2004: Mold Parting Surface Design

[0134] The parting surface of the pre-forging die is kept consistent with the parting surface of the final forging die, based on the blade shape data X''={(x0'', y0'', z0''), (x1'', y1'', z1''), (x2'', y2'', z2'')…(x i '', y i '', z i '')….(x N '', y N '', z N The calculation is obtained by referring to step S1005 of the final forging die design, which involves constructing the parting surface of the pre-forged part.

[0135] S2005: As Figure 14As shown, the parting surface of the pre-forging part is extended in all directions to obtain the parting surface of the pre-forging forming mold, and a module is constructed. The module is divided into an upper pre-forging mold and a lower pre-forging mold by the parting surface of the pre-forging forming mold.

[0136] S2006: Perform Boolean subtraction between the upper and lower pre-forging dies and the pre-forging solid to obtain a pre-forging die with a cavity.

[0137] This embodiment also provides a pre-forging forming die for a blade, which is obtained by the above-described pre-forging forming die design method. It includes an upper pre-forging forming die and a lower pre-forging forming die, and the parting surface of the upper pre-forging forming die and the lower pre-forging forming die is a curved surface formed by the center line of the blade section of the final forging.

[0138] Current blade pre-forging dies are generally made by simply increasing the blade thickness and enlarging the tenon size according to the shape of the final forging, without precisely distributing the metal material to each part. Therefore, current pre-forging dies are equipped with flash grooves around the blade contour to accommodate excess metal. After the blade is pre-forged, this excess flash metal also needs to be removed, resulting in waste of raw materials.

[0139] The design method of the pre-forging die provided in this embodiment designs the cavity shape and size of the pre-forging die using the parameters of the final forging die. Since the shape of the final forging, the shape of the pre-forging, and the shape of the extruded billet are all designed through a series of calculations based on the characteristics of the part, the metal material is gradually deformed and precisely allocated "on demand," meaning there is neither a shortage nor an excess of metal material. Therefore, the pre-forging die designed using this invention does not require the design of flash grooves, and there is no need to trim the edges after pre-forging, thus avoiding waste of raw materials. Furthermore, the deformation between the pre-forging and the final forging obtained by the pre-forging die designed using this invention is precisely designed according to Formula 9, meaning that the deformation of each part of the pre-forging is relatively uniform during final forging, thereby avoiding residual stress caused by uneven deformation and preventing deformation of the forging due to residual stress.

[0140] like Figure 15 As shown, the design method of the extrusion blanking die in this embodiment includes the following steps:

[0141] S3001: For the leaf blade portion, such as Figure 16 As shown, the cross-sectional area of ​​the extruded billet is equal to the cross-sectional area of ​​the corresponding section of the final forging. Therefore, the diameter of the extruded billet corresponding to the j-th section position can be calculated by the following formula:

[0142] ;

[0143] S3002: The dimensions of the tenon part shall be consistent with those of the tenon of the pre-forged part, that is, the cross-section is elliptical, the major semi-axis is a, the minor semi-axis is b, and the direction of the major axis of the ellipse is parallel to the direction of the forging pressure.

[0144] S3003: For the clamps at both ends of the blade, the dimensions of the extruded billet are the same as the dimensions of the final forging, namely d1×L1 and d3×L3.

[0145] S3004: Then design the extrusion die according to the shape of the extrusion blank. The extrusion die includes an ejector pin, an extrusion die, and an extrusion punch.

[0146] like Figure 17 As shown, this embodiment also provides an extrusion blanking die that provides blades, obtained by the above-described extrusion blanking die design method. The extrusion blanking die includes an ejector pin, an extrusion die, and an extrusion punch, and is used for forming on a 630-ton hydraulic press.

[0147] like Figure 16 As shown, this embodiment also provides an extruded blank for a blade. Based on the cavity volume of the blade extrusion blank die described above, the volume of the bar stock is precisely controlled, and an extruded blank is obtained by extrusion. The cross-sectional area of ​​the extruded blank is the same as the cross-sectional area of ​​the corresponding section of the final forging.

[0148] Current blade forging technology does not consider the different cross-sectional dimensions of different parts of the blade when using extruded billets, and the different metal volumes required in different parts of the die during forming. If the bar stock is too small, the forging may not be able to fill certain areas completely. However, if a larger bar stock is used to fill those areas, other areas may experience excessive flash and premature die wear. Furthermore, the flash formed during forging needs to be removed in subsequent processes, resulting in a waste of metal material.

[0149] The design method of the extrusion blanking die in this embodiment is to design the shape and size of the extrusion blanking die cavity according to the characteristics of the final forging die and the pre-forging die. During forming, the bar stock is gradually deformed "on demand" and the metal of each part is distributed "on demand", thereby ensuring that no flash is generated between each forming step. The extrusion blanking of this invention is the first step of "distribution on demand". The extrusion blanking die first makes the tenons at both ends of the blade basically formed, and the amount of metal required for each section of the blade body is also distributed on demand, thus ensuring that no flash is generated during the subsequent pre-forging forming.

[0150] like Figure 18 As shown, step S4 in this embodiment specifically includes the following steps:

[0151] S4001: Cutting: Cutting bar stock into specific specifications and lengths;

[0152] S4002: Apply glass lubricant. Preheat the bar stock to a certain temperature in an oven, and then spray a layer of glass lubricant onto the surface of the bar stock with a spray gun. The thickness of the spray is 0.3~0.5mm.

[0153] S4003: Heating, heating the bar stock to the forging temperature range of the material, and holding it at that temperature for a certain period of time;

[0154] S4004: Extrusion blanking, the heated bar stock of S4003 is taken out and placed into the extrusion blanking die to be extruded into shape to obtain the extruded blank;

[0155] S4005: Surface cleaning of billet, the extruded billet is sandblasted and polished to remove burrs and surface oxide layer from the forging;

[0156] S4006: Spraying glass lubricant. The extruded blank is preheated to a certain temperature in an oven, and then a layer of glass lubricant is sprayed onto the surface of the blank with a spray gun. The spray thickness is 0.3~0.5mm.

[0157] S4007: Heating, reheating the extruded billet to the forging temperature range of the forging material, and holding it at that temperature for a certain period of time.

[0158] S4008: Pre-forging: The extruded billet after heating S4007 is taken out and placed into a pre-forging die to form a pre-forged part;

[0159] S4009: Surface cleaning of pre-forged parts, which involves sandblasting and polishing the pre-forged parts to remove burrs, glass lubricant, oxide layer, etc. from the surface;

[0160] S4010: Spraying glass lubricant. The pre-forged part is heated to a certain temperature in a baking oven, and then a layer of glass lubricant is sprayed onto the surface of the blank with a spray gun. The spray thickness is 0.3~0.5mm.

[0161] S4011: Heating, reheating the pre-forging to the forging temperature range of the forging material, and holding at that temperature for a certain period of time;

[0162] S4012: Final forging: The pre-forging part heated by S4011 is taken out and placed into the final forging mold to form the final forging part.

[0163] At this point, the blade forging is complete. The final forging will then undergo heat treatment and surface cleaning to obtain the finished forging. After passing inspection, it will be packaged and stored.

[0164] Example

[0165] The low-pressure first-stage guide vane of a certain type of engine is made of GH2132 high-temperature alloy. The precision forging process of the blade according to the precision forging forming method provided by this invention is as follows:

[0166] S1: Design the final forging die based on the characteristics of the blade parts;

[0167] S2: Design the pre-forging die based on the characteristics of the final forging die;

[0168] S3: Design extrusion blanking dies based on the characteristics of final forging dies and pre-forging dies;

[0169] S4: Using the designed extrusion blanking die, pre-forging die, and final forging die respectively, the bar stock is extruded, pre-forged, and finally forged to obtain the final forging.

[0170] S4001: Cutting the bar stock into sections Ф16×208±0.5;

[0171] S4002: Apply glass lubricant. Preheat the bar stock to 80~120℃ in an oven, and then spray a layer of glass lubricant onto the surface of the bar stock with a spray gun. The thickness of the spray is 0.3~0.5mm.

[0172] S4003: Heating, heating the bar stock to the forging temperature range of the material, 1100~1150℃, and holding for 10~30 minutes;

[0173] S4004: Extrusion blanking, the heated bar stock of S4003 is taken out and placed into the extrusion die to be extruded into shape to obtain the extruded blank;

[0174] S4005: Surface cleaning of billet. The extruded billet obtained by S4004 is sandblasted and polished to remove burrs and surface oxide layer from the forging.

[0175] S4006: Spraying glass lubricant. Preheat the extruded blank to 80~120℃ in an oven, and then spray a layer of glass lubricant onto the surface of the blank with a spray gun. The spray thickness is 0.3~0.5mm.

[0176] S4007: Heating, heating the extruded billet to the forging temperature range of the material, 1100~1150℃, and holding for 10~30 minutes;

[0177] S4008: Pre-forging: The heated billet of S4007 is taken out and placed into a pre-forging mold to form a pre-forged part;

[0178] S4009: Surface cleaning of pre-forged parts. The pre-forged parts obtained in S4008 are sandblasted and polished to remove burrs, glass lubricant, oxide layer, etc. from the surface of the forging parts.

[0179] S4010: Apply glass lubricant. Preheat the pre-forged part to 80~120℃ in an oven, and then spray a layer of glass lubricant onto the surface of the blank with a spray gun. The thickness of the spray is 0.3~0.5mm.

[0180] S4011: Heating, heating the pre-forged part to the forging temperature range of the material, 1100~1150℃, and holding for 10~30 minutes;

[0181] S4012: Final forging. The pre-forged part after heating in S4011 is taken out and placed into the final forging mold to form the final forging part.

[0182] The design method for the final forging die provided in this embodiment includes the following steps:

[0183] like Figure 19 As shown, the design drawing of a certain type of engine low-pressure first-stage guide vane provides parameter coordinate data for 11 airfoil section curves. The parameter coordinate data of each airfoil form a closed curve connected end to end in space.

[0184] S1001: Based on the 11 airfoil section parameters provided in the blade part design drawing, and according to the algorithms of Formulas 1 to 3 provided in this invention, the airfoil section parameters of the forging blank after adding the allowance are calculated by computer programming. In this embodiment, an allowance of 1.0 mm is added. Figure 20 As shown.

[0185] S1002: Coordinate transformation for calculating the equilibrium angle. Based on the coordinate parameters of the 11 sections plus the allowance obtained in S1001, the equilibrium angle is calculated to be approximately equal to the average of the angles between the chords of sections 1-1 and 11 and the X-axis.

[0186]

[0187] The coordinate parameters of the 11 sections obtained by S1001 after adding the allowance are transformed according to the algorithm provided in Formula 4. The coordinate point parameters of the final forging die blade are calculated by computer programming and saved as data in ".dat" format.

[0188] S1003: Import the ".dat" file containing the section data from the 1st to the 11th sections calculated in S1002 into 3D modeling software (such as UG, ProE, etc.) to design the blade shape of the final forging. Figure 21 As shown.

[0189] S1004: By constructing blade tenons at both ends of the blade body of the final forging and adding process chucks according to the machining clamping and positioning requirements, the three-dimensional modeling design of the final forging can be completed.

[0190] Figure 19The small tenon of the blade part is Ф12×44, and the large tenon is Ф35×5. According to the machining allowance requirements, the tenon of one end of the blade is designed to be Ф16×45mm and Ф40×8mm, and the other end is designed with a chuck with a diameter of d3 and a length of 20mm.

[0191] To facilitate extrusion blanking, the chuck diameter d3 is designed based on the blade end face cross-section. Using formula 5, the cross-sectional area of ​​the blade end face is calculated to be 201 mm². 2 From this, it can be calculated that

[0192]

[0193] S1005: Based on the data of the 1st to 11th cross sections obtained from S1002, the center lines of the blade cross sections of the 1st to 11th final forgings are calculated by computer programming using the algorithms provided by Formulas 6 to 7 as the parting lines of the blade body of the final forging die, and the data is saved in the format of ".dat".

[0194] Import the calculated parting line data (".dat" file) from sections 1 to 11 into 3D modeling software (UG, ProE, etc.). Use these 11 curves to generate the parting surface of the blade portion of the final forging.

[0195] S1006: As Figure 22 As shown, by expanding the parting surface of the blade section of the final forging in all directions, the parting surface of the entire mold can be obtained. Finally, a module (length × width × height is 300 × 200 × 240) is constructed. The module is divided into the upper mold and the lower mold of the final forging by the parting surface.

[0196] S1007: By performing Boolean subtraction between the upper and lower final forging dies and the final forging solid, the final forging die with cavity can be obtained.

[0197] At this point, the design of the final forging die is complete.

[0198] The design method for pre-forging forming dies provided in this embodiment includes the following steps:

[0199] S2001: Based on the coordinate parameters of the blade section of the final forging die mentioned above, the coordinate parameters of the pre-forming die blade profile are calculated by computer programming according to the algorithms provided in Formulas 8 to 9. In Formula 9, δ is the deformation reduction of the final forging. The value of δ should not be less than the minimum critical deformation specified for the blade material. For GH2132 alloy, δ should be > 0.2. The value of 0.25 is used for calculation. The calculated parameters are saved in a file in ".dat" format.

[0200] S2002: Import the ".dat" data of the blade section of the 11 pre-forging dies calculated in S2001 into 3D modeling software (UG, ProE, etc.) to generate the blade body of the pre-forging die, such as... Figure 23 As shown.

[0201] S2003: Design the tenons or clamps at both ends of the pre-forging die blade according to the shape of the tenons or clamps at both ends of the final forging die blade.

[0202] The dimensions of the small tenons and clamps remain unchanged; that is, the dimensions of the small tenons and clamps at both ends of the pre-forged part are still Ф16×45mm and Ф16×20mm, respectively. The cross-section of the large tenon is designed as an ellipse, with the major semi-axis of the ellipse being a and the minor semi-axis being b. Parameters a and b are determined according to Formula 10, i.e.

[0203]

[0204] The shape of the obtained pre-forged part is as follows Figure 24 As shown.

[0205] S2004: Mold parting surface design,

[0206] The parting surface of the pre-forging die follows the parting surface of the final forging die. The parting surface of the pre-forging component is calculated from the coordinate parameters of the blade section of the final forging die.

[0207] S2005: Expand the parting surface of the pre-forging part in all directions to obtain the parting surface of the pre-forging forming mold, and construct a module (length × width × height is 300 × 200 × 240). Divide the pre-forging forming mold into an upper pre-forging mold and a lower pre-forging mold using the parting surface of the pre-forging forming mold.

[0208] S2006: Perform Boolean subtraction between the upper and lower pre-forging dies and the pre-forging solid part to obtain a pre-forging die with a cavity, such as... Figure 25 As shown. The design of the pre-forging die is now complete.

[0209] The design method for extrusion blanking molds provided in this embodiment includes the following steps:

[0210] S3001: For the leaf blade portion, such as Figure 26 As shown, the cross-sectional area of ​​the extruded billet is equal to the cross-sectional area of ​​the corresponding section of the final forging. Therefore, the areas of the 1st to 11th blade sections are calculated using Formula 11 as follows: 201 mm² 2 202.96mm 2 207.38mm 2 213.94mm 2 221.40mm 2 229.32mm 2237.56mm 2 245.79mm 2 255.33mm 2 266.79mm 2 283.91mm 2 Therefore, the corresponding extruded blank diameters for the blade body are calculated to be Ф16, Ф16.08, Ф16.25, Ф16.50, Ф16.79, Ф17.08, Ф17.39, Ф18.03, Ф18.43, and Ф19.01, respectively.

[0211] S3002: For the dimensions of the tenon, the large tenon of the extruded blank is consistent with the large tenon of the pre-forged part, that is, the cross-section is elliptical, the major half-axis is 25mm and the minor half-axis is 16mm. The small tenon of the extruded blank is consistent with the small tenon of the pre-forged part, that is, Ф16×45mm.

[0212] S3003: The shape of the extruded billet is designed according to the shape parameters of the final forging. For the clamps at both ends of the blade, the size of the extruded billet is consistent with the size of the final forging, which is Ф16×20mm.

[0213] S3004: Then design the extrusion die according to the shape of the extruded billet, such as Figure 17 As shown, the extrusion die consists of a push rod, an extrusion die, and an extrusion punch.

[0214] The extrusion blank is made of Ф16 bar stock, and the blank length is calculated to be 208mm based on the volume of the extrusion blank.

[0215] Alternatively, the forming equipment can be a general-purpose hydraulic press or a hot forging press.

[0216] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing a pre-forging die for blades, characterized in that, Includes the following steps, S2001: Calculate the coordinate parameters of the blade section of the pre-forging die based on the coordinate parameters and area of ​​the blade section of the final forging die and the deformation reduction of the final forging. S2002: Import the coordinate parameters of the blade section of the pre-forging die calculated in step S2001 into the 3D modeling software to generate the shape of the blade body of the pre-forging part. S2003: Calculate the dimensional parameters of the tenons and process clamps at both ends of the blade of the pre-forged part based on the dimensional parameters of the tenons and process clamps at both ends of the blade of the final forging die. S2004: Using the center lines of the blades of the first to Mth blade sections of the final forging as parting lines, construct the parting surface of the pre-forging; S2005: Expand the parting surface of the pre-forging part in all directions to obtain the parting surface of the pre-forging forming mold, and construct a module. The module is divided into the pre-forging upper mold and the pre-forging lower mold through the parting surface of the pre-forging forming mold. S2006: Perform Boolean subtraction between the upper and lower pre-forging dies and the pre-forging solid to obtain a pre-forging die with a cavity; S2004 specifically includes the following steps. The coordinate parameters of the blade section of the final forging die calculated by S2001 are X''={(x0'',y0'',z0'')(x1'',y1'',z1'')(x2'',y2'',z2'')…(x i '', y i '', z i '')…. (x N '', y N '', z N The fractal line is calculated using the following algorithm: make ; Let the coordinates of any point on the final forged blade profile curve be (x... i '', y i '', z i ''), in the formula It is a point (x) i '', y i '', z i The first derivative at '') It is a point (x) i '', y i '', z i The second derivative at '') then R i Representative point (x) i '', y i '', z i The radius of curvature at '') Start the search from point 1, if R is the radius of the inlet and outlet arc of the final forged blade. These are then labeled as flag1, flag2, flag3, and flag4, representing the positions of the tangent points between the inlet and outlet arcs of the blade and the blade base / back curve. The coordinate parameters of the blade centerline point are: ； The calculated parting surface section curve data is imported into 3D modeling software to generate the parting surface of the blade.

2. The design method for the pre-forging die of the blade according to claim 1, characterized in that, S2001 specifically includes the following steps. Given the coordinate point parameters X'' of the blade profile of the final forging die: X'' = {(x0'', y0'', z0''), (x1'', y1'', z1''), (x2'', y2'', z2'') ... (x i '', y i '', z i '')…. (x N '', y N '', z N '')}, The coordinate parameters of the blade profile of the pre-forging die are defined as X'''={(x0''', y0''', z0'''), (x1''', y1''', z1'''), (x2''', y2''', z2''')...(x i ''',y i ''', z i ''')…. (x N ''',y N ''', z N ''')} , The blade profile coordinate parameters of the pre-forging die can be calculated using the following algorithm: make ; but ; In the formula, δ is the deformation reduction of the final forging, and the value of δ is not less than the minimum critical deformation specified for the blade material. This represents the area of ​​the j-th airfoil section of the final forging die; This represents the area of ​​the j-th airfoil section of the pre-forging die; When calculating the blade section coordinate parameters of the pre-forging die, first let Calculate the ordinate using Formula 9. The value is then substituted into formula 8 to calculate... Finally, substitute the values ​​into formula 9 to calculate the x-coordinate. The value of .

3. The design method for the pre-forging die of the blade according to claim 1, characterized in that, In S2003, the cross-section of the tenon of the final forging die blade is circular, and the cross-section of the tenon is elliptical, with the major axis of the ellipse parallel to the forging pressure direction.

4. The design method for the pre-forging die of the blade according to claim 3, characterized in that, The tenon of the final forging die blade has a circular cross-section with a diameter of d2. The tenon has an elliptical cross-section, with a major semi-axis of a and a minor semi-axis of b. Then the parameters a and b are determined according to the following formula: ； In the formula, δ is the deformation reduction in the final forging.

5. The design method for the pre-forging die of the blade according to claim 1, characterized in that, In S2003, the cross-sectional area of ​​the process chuck is equal to the area of ​​the blade end face cross-section to which it is connected.

6. The design method of the pre-forging die for the blade according to claim 1, characterized in that, The material for the final forging is GH2132 alloy.

7. The design method of the pre-forging die for the blade according to claim 6, characterized in that, The deformation reduction δ of the final forging is greater than 0.

2.

8. The design method of the pre-forging die for the blade according to claim 7, characterized in that, The deformation reduction in the final forging is δ=0.

25.

9. A pre-forging die for blades, characterized in that, The blade pre-forging die design method according to any one of claims 1 to 8 is obtained, comprising a pre-forging upper die and a pre-forging lower die, wherein the parting surface of the pre-forging upper die and the pre-forging lower die is a curved surface formed by the center line of the blade section of the final forging.

Images