Grinding and milling combined machining method for blade

Abstract

The grinding and milling combined machining method for the blade comprises the steps that firstly, a blade blank is primarily machined, and workbenches are formed at the two ends of the blade blank respectively; step 2, forming a coordinate system of a detection program based on the part processed in the step 1 according to an aero-engine blade median calculation drawing method so as to detect the size of the part; 3, grinding the basin back radial surface of the margin plate of the part qualified in size detection to form a to-be-ground blade with an upper groove and a bottom arc surface; 4, the allowance part on the blade to be ground is removed through the linear cutting technology, wherein the upper side groove to be ground and the bottom arc face of the blade to be ground are formed in the blade; and 5, the blade to be ground and machined after being machined in the step 4 is fastened in the basin back direction, the axial direction and the feeding and discharging direction through a flange grinding plate clamp tool, the groove and the arc face are ground and machined to the size meeting the design requirement, and the machining efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of blade processing technology, and particularly relates to a grinding and milling composite processing method for blades. Background Art

[0002] The gas turbine is one of the key projects established in accordance with the requirements of the national two-engine special project. Among them, the stator blade with a double-edge plate structure is a typical key component, and it still mainly adopts a milling-based processing method, resulting in great room for improvement in aspects such as part deformation suppression, material removal speed, and finished product brightness performance during the processing. Currently, the proportion of superalloy materials in the field of gas turbine blades is increasing day by day. The traditional single milling processing method is becoming increasingly inadequate in terms of efficiency and quality, and it is urgent to solve the following problems emerging under the traditional processing method:

[0003] (1) Large torsion part deformation. In the traditional single milling processing method, with a single milling operation using a center hole clamping, the material removal in a single process is large, the machining accuracy requirements are high, the machining milling force is large, and due to the thin airfoil part of the double-edge plate stator blade itself, it is extremely easy to cause irregular and large-amplitude torsion deformation of the airfoil after processing, affecting the product quality;

[0004] (2) Difficult processing of superalloy materials. In the field of gas turbine blade processing, there is currently a trend of die-forged blanks mainly made of superalloy materials, and superalloy materials belong to difficult-to-process materials with high strength and hardness. When using the traditional single milling processing method, there are a series of problems such as large cutting force, high cutting temperature, slow material removal, and serious tool wear;

[0005] (3) Composite of multiple-size R structures, large tool requirements, and high processing difficulty. In the processing of this type of stator blade, it is necessary to process multiple sizes of R at multiple parts such as the intake and exhaust edges of the upper and lower edge plates. If the traditional single milling processing method is used, multiple tools need to be used for processing, resulting in high production costs, and due to frequent tool changes, the processing efficiency will be greatly reduced.

[0006] In view of this, the present invention is specifically proposed. Summary of the Invention

[0007] The purpose of the present invention is to provide a grinding and milling composite processing method for blades to solve the technical problem of low processing efficiency of the existing technology. There are many technical beneficial effects of the technical solution of this case, as introduced below:

[0008] A grinding and milling composite processing method for blades, which is applicable to the processing of stator blades with a double-edge plate structure of a gas turbine by a numerical control machine tool. The method includes,

[0009] Step 1: Rough machine the blade blank, and worktables are respectively formed at both ends of the blade blank. The top surface, the inlet edge surface, and the back surface of the process table are used as the positioning references for NC milling of the blade;

[0010] Carry out airfoil machining and flange machining according to the blade design specifications. The outer arc of the inlet edge of the upper flange of the blade is used as the A-reference outer arc, and the vertical surface of the inlet edge of the upper flange of the blade is used as the B-reference step. Among them, the A-reference outer arc and the B-reference step are machined in sequence and machined to the accuracy range required by the design specifications. Allowances for grinding are left for the remaining parts. The progressive approximation triple R machining method and the machining method of the curved generatrix are used to form a continuous curve, and the continuous curve is used as the design generatrix;

[0011] Step 2: Based on the parts machined in Step 1, establish the coordinate system of the inspection program according to the median value calculation and drawing method of the aero-engine blade to perform dimensional inspection on the parts;

[0012] For the parts that pass the dimensional inspection, grind the radial surfaces of the concave and convex sides of the flange to form the blade with the groove to be ground on the upper side and the bottom arc surface;

[0013] For the blade to be ground, use the wire cutting process to remove the surplus parts on the blade to be ground. Among them, the surplus parts include forming a groove that meets the design requirements and has a surplus on the top surface of the large flange to be ground and forming an arc surface that meets the design and has a surplus on the bottom surface of the large flange for grinding;

[0014] Through the grinding flange fixture tooling, fasten the blade to be ground processed in Step 4 in the concave-convex direction, the axial direction, and the inlet and outlet directions, and grind the groove and the arc surface to the dimensions required by the design.

[0015] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0016] (1) Significantly reduce the debugging difficulty of milling. In the milling part of the method proposed in this patent, except for very few dimensions that need to be machined in place, most of the dimensions are for grinding, so allowances are left. When debugging the radial surface of the concave and convex sides in milling: the tolerance zone is expanded by 2.5 times; when machining the R of the upper and lower flanges in milling, because allowances are left for grinding, the purpose of not machining or reducing the tolerance requirements can also be achieved. Therefore, compared with the traditional single milling method, the debugging difficulty in milling is significantly reduced;

[0017] (2) The complex dimensions can be processed to the final state in one go, significantly improving the surface quality. In the grinding process of the method proposed in this patent, the radial surface of the grinding basin is processed first, then the radial surface of the grinding back is processed, and finally the upper and lower edge plates of the radial grinding are processed. On the one hand, compared with the traditional single milling method, the advantages of grinding can be fully utilized, significantly reducing the surface roughness of the parts and improving the brightness performance, so that the surface roughness after processing is reduced to Ra0.2. On the other hand, in the process of grinding the upper and lower edge plates, all planes of the upper and lower edge plates of the blade and Rs with different sizes can be processed to the final state in one go, ensuring the quality consistency of the blade size processing while guaranteeing excellent surface quality;

[0018] (3) Improve the processing efficiency of superalloy materials. Grinding has inherent advantages over milling in terms of efficiency. Taking the radial surface process of the grinding basin as an example, the single program time for precision grinding of the large and small edge plates only needs two minutes and thirty seconds each to reach the finished product size. And for a large number of parts, the grinding method involved in the patent proposed by this institute is used to process them to the finished product size, which can greatly reduce the processing time required for parts processing and improve the actual processing efficiency. Brief Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a schematic diagram of the part where R processing needs to be carried out in the method of the present invention;

[0021] Figure 2 It is a schematic diagram of positioning the processing workbench in the method of the present invention;

[0022] Figure 3 It is a schematic diagram of the sequence of the milling method in the method of the present invention;

[0023] Figure 4 It is a schematic diagram of constructing a coordinate system in the method of the present invention;

[0024] Figure 5 It is a schematic diagram of grinding grooves and arc surfaces;

[0025] Figure 6 It is a progressive approximation triple R processing method;

[0026] Figure 7 It is a micro rounding processing method for a curved generatrix;

[0027] Figure 8 It is the processing sequence of the groove on the upper side and the arc surface at the bottom of the blade. Detailed Implementation Modes

[0028] The following specific examples illustrate the implementation modes of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0029] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present invention, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. Additionally, this device and / or this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0030] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention schematically. The drawings only show the components related to the present invention, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be arbitrarily changed, and the layout type of its components may also be more complex.

[0031] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the aspects can be practiced without these specific details. To make the personnel in this technical field better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the drawings and specific implementation modes. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0032] As Figures 1 to 8The blade grinding and milling composite processing method shown in the figure is suitable for machining the stator blades of the double-edge plate structure of the gas turbine by CNC machine tools. Specifically, Figure 1 The marked parts are the core processing positions, which are processed by combining milling and grinding. The methods include:

[0033] Step 1: Perform preliminary processing on the blade blank, such as Figure 2 As shown in FIG. 1 , workbenches are formed at both ends of the blade blank, and the top surface, air inlet side surface, and back surface of the process table are used as positioning references for CNC machine tool milling. Figure 2 As shown, the right side of the workbench is the air intake side, the top side is the positioning side, and the left side is the exhaust side;

[0034] The blade shape and edge plate are processed according to the blade design specification, and the outer arc of the air inlet edge of the blade upper edge plate is used as the A reference outer arc, and the vertical surface of the air inlet edge of the blade upper edge plate is used as the B reference step. The A reference outer arc and the B reference step are processed in sequence and processed to the accuracy range required by the design specification. The remaining parts are left with grinding allowances. Generally, there is a horizontal distance between the vertical surface of the air inlet edge of the blade upper edge plate and the air inlet edge of the blade lower edge plate, and a 0.2mm allowance is left on the radial surface of the basin back. The asymptotic approximation triple R processing method and the bending generatrix processing method are used to form a continuous curve, and the continuous curve is used as the design generatrix. Preferably, as Figure 3 As shown, the order of blade shape processing of the blade blank is blade root, blade crown, and the part between the root and crown, and rough and fine processing methods are adopted in turn. Among them, the processing method for the connection between the root crown and the part between the root crown is the progressive approximation triple R processing method.

[0035] For further information, see Figure 6 As shown, the asymptotic approach triple R processing method mentioned above includes:

[0036] Select a round nose cutter with suitable cutter type to process the root crown position into R n+1 The size of R n+1 , R n and R n-1 The matching ball cutter is used to finish the connection between the root crown and the blade profile in sequence. n is a positive integer greater than or equal to 4, where n When the corresponding ball cutter is used for processing, it can n+1 With size R n-1 The location of the realization size R n The smooth transition of the arc at the transition position ensures the accuracy and quality of the processing, and lays the foundation for subsequent grinding to ensure uniform overall roughness. For example, a round nose cutter with a diameter of 25mm and an R of 5mm is selected to process a certain type of blade. The size R n+1 , R n and R n-1They are R5, R4, and R3. The round nose cutter first machines the machining position to a size of R5, which belongs to rough machining. Then, ball cutters with radii of 5 and 4 are used to further trim the machining area, successively machining it to the R5 and R4 sizes, which belongs to semi-finishing. Finally, a ball cutter with a radius of 3 is used to machine the machining area to the required R3 size of the design, which belongs to finishing. That is, the round nose cutter only removes the surplus and makes a preliminary shape, and then three different ball cutters are used to gradually machine the size required for the part.

[0037] Further, refer to Figure 7 , for the machining of the small fillets at the root-crown part in step 1, the machining method with a curved generatrix is used, which includes,

[0038] Adjust the machining direction of the round nose cutter through the numerical control machine tool. Among them, after the crown generatrix of the blade blank is tangent to the fillet r n required by the design of the blade small flange plate, it is tangent to the large arc of N times the fillet r n of the blade to be machined. Generally, the selection of N times is related to the current blade to be machined. For example, the N-fold coefficient of a certain type of gas turbine blade is selected as 3;

[0039] Set a straight line segment with a preset length in the horizontal direction of the inlet and exhaust edges of the flange of the blade blank at the end of the large arc (the direction of the tool path determines the end of the large arc). This straight line segment is used to block the tool path. If this straight line segment is not set, during the actual machining of the blade, the tool machining is not restricted, and it is easy to cut the body part of the blade, that is, the blank part is cut excessively;

[0040] Connect the straight line segment, the fillet r n and the large arc into a continuous curve, and use the continuous curve as the original generatrix to construct the design curve. That is, replace the design curve constructed by the original generatrix in the traditional design with the continuous curve. The purpose is: Based on this, the programming of the crown flange program can be carried out, and when using a R3 ball cutter for root cleaning machining, the machining of the small fillets at the crown can be realized. Through the continuous curve for the programming of the crown and flange program, during the actual root cleaning machining, the machining of the flange and the fillet r3 can be realized simultaneously.

[0041] Step 2: Based on the part machined in step 1, form the coordinate system of the inspection program according to the median value calculation and drawing method of the aero-engine blade to inspect the dimensions of the part. Specifically,

[0042] As Figure 4 shown, the formation of the coordinate system of the inspection program includes determining the median value of the B-reference step according to the median value calculation and drawing method of the aero-engine blade, and constructing the first construction reference based on the median value of the B-reference step;

[0043] The median of the B reference step and the first construction reference are used to fit the X-axis of the detection coordinate system by the least squares method. The basin surface of the process table is used as the second construction reference, and the Y-axis of the detection coordinate is established in the same way. The outer arc of the A reference is used as the third construction reference, and the Z-axis of the detection coordinate system is established in the same way. Finally, the coordinate system of the detection program is formed, and the detection is carried out by using the methods or equipment in the existing technology.

[0044] Step 3: After the dimensional inspection is qualified, the parts are subjected to grinding on the radial surfaces of the basin and back of the flange, as Figure 4 shown, to form the to-be-ground upper side groove and the bottom arc surface blade. Among them, the surfaces facing the reader are the large flange basin radial surface and the small flange basin radial surface, and the surfaces facing away from the reader are the large flange back radial surface and the small flange back radial surface. An integrated tooling for clamping and measuring the radial surface of the basin is used to position and fasten the blade blank, including grinding the radial surfaces of the blade basin and back, and grinding the radial surfaces of the basin and back of the large flange and the radial surfaces of the basin and back of the small flange. Preferably, the grinding of the radial surface of the blade basin is carried out first. Specifically,

[0045] On the basin-back direction of the blade, the back surface of the process table is used as the positioning reference, and the hook-shaped pressing plate of the integrated tooling is used to press the upper and lower flanges to complete the positioning of the basin-back direction of the blade. The radial surfaces of the upper and lower flanges of the basin are simultaneously rough-ground by the grinding wheel with a margin of less than 0.15 mm left, and then the radial surface of the large flange basin is finely ground and the radial surface of the small flange basin is finely ground in sequence. After the grinding process, a sliding dial indicator inspection work is used for inspection, and the dial reading is -0.03 to +0.03 mm, and the reading difference is not greater than 0.03 mm. In the traditional process, a grinding wheel for signal adaptation is made by using a roller.

[0046] The integrated tooling for clamping and measuring the back radial surface is used to position the basin-back direction of the blade, and when the B reference step is close to the positioning block of the integrated tooling for clamping and measuring the back radial surface, it is used as the positioning reference. The back radial surfaces of the upper and lower flanges are simultaneously rough-ground by the grinding wheel with a margin of less than 0.15 mm left for the finished size, and then the radial surface of the large flange basin is finely ground and the radial surface of the small flange basin is finely ground in sequence. After the grinding process, a sliding dial indicator inspection work is used for inspection, and the dial reading is -0.023 to +0.023 mm.

[0047] Step 4: The to-be-ground upper side groove and the bottom arc surface blade adopt the wire cutting process to remove the surplus part on the to-be-ground blade. Among them, the surplus part includes forming a groove on the top surface of the large flange of the to-be-ground blade that meets the design requirements and has a margin, generally 1 mm thicker than the design requirements, and forming an arc surface on the bottom surface of the ground large flange of the blade that meets the design and has a margin, generally 1 mm thicker than the design requirements. After milling and cutting, as Figure 5 shown, a groove on the top surface and an arc surface on the bottom surface are formed.

[0048] Step 5: Fasten the blade with the upper side groove and bottom arc surface to be ground after the processing in Step 4 in the back of the basin direction, axial direction, and inlet and outlet directions by using the fixture tooling for the edge grinding plate, and grind the groove and arc surface to the dimensions required by the design, that is, grind the 1 mm allowance, and select different grinding wheels for grinding at each position. Since the transition at the Rn position in Step 1 is smooth, the difficulty of grinding wheel grinding is reduced. Specifically,

[0049] Step 5.1: Fasten the blade to be ground after the allowance is removed in the back of the basin direction, axial direction, and inlet and outlet directions by using the fixture tooling for the edge grinding plate;

[0050] Step 5.2: Select the flat roller for the upper edge plate groove and the R5 roller for grinding both sides of the upper edge plate for the upper edge plate, and select the R3 roller for grinding the inlet edge of the lower edge plate, the R1 roller for grinding the exhaust edge of the lower edge plate, and the R3 roller for grinding the exhaust edge of the lower edge plate, and trim the grinding wheels to match the forming shapes of the rollers of each model;

[0051] Step 5.3: Grind different parts of the blade with grinding wheels of each model, see Figure 8 , specifically,

[0052] Step 5.3.1: Use the R5 grinding wheel for both sides of the upper edge plate in Step 5.2, and adopt the method of initially rough grinding to remove 0.4 mm of allowance, secondarily initially grinding to remove 0.4 mm of allowance, semi-finish grinding to remove 0.1 mm of allowance, and finish grinding to remove 0.1 mm of allowance to the finished product size to machine the R5 size surface on the exhaust side of the upper edge plate of the blade;

[0053] Step 5.3.2: After using the R5 roller for both sides of the upper edge plate in Step 5.2 to grind and trim the grinding wheel, use the grinding wheel, and adopt the method of initially rough grinding to remove 0.4 mm of allowance, secondarily initially grinding to remove 0.4 mm of allowance, semi-finish grinding to remove 0.1 mm of allowance, and finish grinding to remove 0.1 mm of allowance to the finished product size to machine the R5 size surface on the inlet side of the upper edge plate of the blade;

[0054] Step 5.3.3: After using the flat roller for the upper edge plate groove in Step 5.2 to grind and trim the grinding wheel, use the grinding wheel, and adopt the method of initially rough grinding to remove 0.4 mm of allowance, secondarily initially grinding to remove 0.4 mm of allowance, semi-finish grinding to remove 0.1 mm of allowance, and finish grinding to remove 0.1 mm of allowance to the finished product size to machine the flat surface of the upper edge plate groove of the blade;

[0055] Step 5.3.4: After using the flat roller for the upper edge plate groove in Step 5.2 to grind and trim the grinding wheel, use the grinding wheel, and adopt the method of initially rough grinding to remove 0.4 mm of allowance, secondarily initially grinding to remove 0.4 mm of allowance, semi-finish grinding to remove 0.1 mm of allowance, and finish grinding to remove 0.1 mm of allowance to the finished product size to machine the outer arc surface of the exhaust side of the upper edge plate of the blade;

[0056] Step 5.3.5: After grinding the R3 roller on the intake edge of the lower blade plate in Step 5.2 to dress the grinding wheel, use the grinding wheel to machine the R3 dimension surface of the intake edge of the lower blade plate by rough grinding for the first time to remove a margin of 0.4 mm, rough grinding for the second time to remove a margin of 0.4 mm, semi-finish grinding to remove a margin of 0.1 mm, and finish grinding to remove a margin of 0.1 mm to the finished size.

[0057] Step 5.3.6: After grinding the R1 roller on the exhaust edge of the lower blade plate in Step 5.2 to dress the grinding wheel, use the grinding wheel to machine the R1 dimension surface of the exhaust edge of the lower blade plate by rough grinding for the first time to remove a margin of 0.4 mm, rough grinding for the second time to remove a margin of 0.4 mm, semi-finish grinding to remove a margin of 0.1 mm, and finish grinding to remove a margin of 0.1 mm to the finished size.

[0058] Step 5.3.7: After grinding the flat roller in the groove of the upper blade plate in Step 5.2 to dress the grinding wheel, use the grinding wheel to machine the inner arc surface at the lower end of the lower blade plate by rough grinding for the first time to remove a margin of 0.4 mm, rough grinding for the second time to remove a margin of 0.4 mm, semi-finish grinding to remove a margin of 0.1 mm, and finish grinding to remove a margin of 0.1 mm to the finished size.

[0059] Step 5.3.8: After grinding the R3 roller on the exhaust edge of the lower blade plate in Step 5.2 to dress the grinding wheel, use the grinding wheel to machine the R3 dimension surface of the exhaust edge of the lower blade plate by rough grinding for the first time to remove a margin of 0.4 mm, rough grinding for the second time to remove a margin of 0.4 mm, semi-finish grinding to remove a margin of 0.1 mm, and finish grinding to remove a margin of 0.1 mm to the finished size.

[0060] Step 5.3.9: After grinding the flat roller in the groove of the upper blade plate in Step 5.2 to dress the grinding wheel, deflect the angle to machine the inner chamfer in the groove of the intake edge of the upper blade plate.

[0061] Step 5.3.10: After grinding the flat roller in the groove of the upper blade plate in Step 5.2 to dress the grinding wheel, deflect the angle to machine the inner chamfer in the groove of the exhaust edge of the upper blade plate.

[0062] Step 5.3.11: After grinding the flat roller in the groove of the upper blade plate in Step 5.2 to dress the grinding wheel, deflect the angle to machine the outer chamfer in the groove of the exhaust edge of the upper blade plate.

[0063] Step 5.3.12: After grinding the flat roller in the groove of the upper blade plate in Step 5.2 to dress the grinding wheel, deflect the angle to machine the chamfer on the exhaust edge of the lower blade plate.

[0064] In addition to the process platform on the blade being machined in one step, there is a margin left on the remaining parts of the blade, and grinding wheels of different models are selected for grinding at different positions of the margin, which can ensure the roughness of each position. Compared with pure milling, it not only reduces the difficulty of overall milling of the blade, but also keeps the roughness of each local part of the part consistent. Especially for blades made of superalloy materials, the milling-filming combination method can shorten the processing time. The traditional method uses a single milling and cutting method for processing, and it is difficult to achieve uniform roughness at each position of the finished blade. However, the method of the present invention focuses on the grinding composite processing method, and uses the method of promoting milling with grinding and combining grinding and milling for processing. The grinding of parts such as the upper and lower flange plates, the basin radial surface, and the back radial surface after milling is formed in one step. On the one hand, it can significantly improve the removal efficiency for superalloy materials compared with the traditional single milling method. On the other hand, it can give full play to the advantages of grinding processing, greatly reduce the surface roughness of the part and improve the lightness performance. Therefore, the present invention has developed a new processing method of "promoting milling with grinding", and the roughness of the blade surface can be improved by combining grinding and milling.

[0065] The above has introduced the product provided by the present invention in detail. Specific examples are used in this article to elaborate on the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be pointed out that for those of ordinary skill in the art of this technology, without departing from the principle of the invention, several improvements and modifications can still be made to the invention, and these improvements and modifications also fall within the protection scope of the invention claims.

Claims

1. A milling and grinding composite machining method for blades, applicable to the machining of stator blades with double-edge plate structure of gas turbines by numerically controlled machine tools, characterized in that, The method includes: Step 1: Rough machine the blade blank, and worktables are respectively formed at both ends of the blade blank, and the top surface, intake edge surface, and back surface of the process table are used as the positioning reference for CNC milling of the blade; Carry out airfoil machining and flange machining according to the blade design specifications, and use the outer arc of the intake edge of the upper flange of the blade as the A-reference outer arc and the vertical surface of the intake edge of the upper flange of the blade as the B-reference step. Among them, the A-reference outer arc and the B-reference step are machined in sequence and machined to the accuracy range required by the design specifications. The remaining parts all have grinding allowances, and the progressive approximation triple R machining method and the machining method of the bending generatrix are used to form a continuous curve, and the continuous curve is used as the design generatrix; Step 2: Based on the part machined in Step 1, form the coordinate system of the inspection program according to the median value calculation and drawing method of the aero-engine blade to inspect the dimensions of the part; After the part passes the dimension inspection, grind the radial surfaces of the concave and convex sides of the flange to form a blade with a to-be-ground upper groove and a bottom arc surface; Use wire cutting technology to remove the surplus part on the blade to be ground in the blade with a to-be-ground upper groove and a bottom arc surface. Among them, the surplus part includes forming a groove that meets the design requirements and has a surplus on the top surface of the large flange to be ground and forming an arc surface that meets the design and requires a surplus on the bottom surface of the large flange to be ground; Fasten the blade to be ground processed in Step 4 in the concave-convex direction, axial direction, and inlet and outlet directions through the flange grinding fixture tooling, and grind the groove and arc surface to the dimensions required by the design; 2. The milling and grinding compound machining method of the blade according to claim 1, characterized in that, In the airfoil machining of the blade blank in Step 1, the sequence is the blade root, blade crown, and the part between the root and crown, and the rough and finish machining methods are used in sequence. Among them, the machining method at the connection between the root and the part between the roots is the progressive approximation triple R machining method; 3. The milling and grinding composite machining method of the blade according to claim 2, wherein, The progressive approximation triple R machining method includes: Select a round nose cutter with a suitable tool shape to rough machine the root crown position to a size of R n+1 , and then use ball cutters respectively adapted to the sizes R n+1 , R n and R n-1 to finish machining the connection between the root crown and the blade profile in sequence. n is a positive integer greater than or equal to 4. Among them, when the ball cutter corresponding to the size R n is used for machining, it can achieve a smooth transition of the arc at the transition position between the size R n+1 and the size R n-1 at the position of the size R n .

4. The milling and grinding composite machining method for the blade according to claim 2, characterized in that The machining of the small fillets at the part between the roots in Step 1 uses the machining method of the bending generatrix, which includes: Adjust the machining direction of the round nose cutter through a numerical control machine tool. Among them, after the crown bus of the blade blank is tangent to the chamfered round r required by the blade small flange design, it is tangent to the large arc of N times the chamfered round r of the blade to be machined. n After being tangent, it is tangent to the N-fold chamfered round r of the blade to be machined. n of the large arc; Set a straight line segment with a preset length in the horizontal direction of the intake and exhaust edges of the flange of the blade blank at the end of the large arc; Connect the direct segment and the rounded corner r n and the large arc into a continuous curve, and replace the original generatrix with the continuous curve to construct a designed curve.

5. The milling and grinding compound processing method of the blade according to claim 1, characterized in that, The coordinate system for forming the inspection program in Step 2 includes: Determine the median value of the B-reference step according to the median value calculation and drawing method of the aero-engine blade, and construct the first construction reference with the median value of the B-reference step; The median value of the B-reference step and the first construction reference are used to fit the X-axis of the inspection coordinate system by the least squares method. The basin surface of the process table is used as the second construction reference, and the Y-axis of the inspection coordinate is established in the same way. The A-reference outer arc is used as the third construction reference, and the Z-axis of the inspection coordinate system is established in the same way, and finally the coordinate system of the inspection program is formed; 6. The milling and grinding composite machining method of the blade according to claim 1, characterized in that, The grinding of the radial surfaces of the concave and convex sides after the part passes the dimension inspection in Step 3 includes: Use the integrated tooling for clamping and measuring the radial surfaces of the basin to position and fasten the blade blank, and grind the radial surfaces of the basin and the back of the blade. Among them, With the back of the process table as the positioning reference in the back direction of the blade basin, the upper and lower edge plates are pressed by the hook-shaped pressing plate of the integrated tooling to complete the positioning in the back direction of the blade basin. The grinding wheels are used to rough grind the radial surfaces of the upper and lower edge plates in the basin direction simultaneously, leaving a margin of less than 0.15 mm. Then, the radial surface of the large edge plate in the basin is finely ground in sequence, and the radial surface of the small edge plate in the basin is finely ground. After grinding, a sliding dial gauge is used for inspection. The dial gauge reading is -0.03 to +0.03 mm, and the reading difference is not greater than 0.03 mm. The integrated tooling for clamping and measuring the radial surface of the back is used to position the back direction of the blade basin. When the B-reference step is closely against the positioning block of the integrated tooling for clamping and measuring the radial surface of the back, it serves as the positioning reference. The grinding wheels are used to rough grind the radial surfaces of the upper and lower edge plates in the back direction simultaneously to the finished size, leaving a margin of less than 0.15 mm. Then, the radial surface of the large edge plate in the basin is finely ground in sequence, and the radial surface of the small edge plate in the basin is finely ground. After grinding, a sliding dial gauge is used for inspection. The dial gauge reading is -0.023 to +0.023 mm.

7. The milling and grinding composite machining method for the blade according to claim 6, characterized in that, The thickness of the margin in Step 4 is less than 1 mm.

8. The milling and grinding composite machining method of the blade according to claim 1, characterized in that, Step 5 includes Step 5.1: The blade with the upper side groove and bottom arc surface after removing the margin is fastened in the back direction, axial direction, and inlet and outlet directions through the edge plate grinding fixture tooling. Step 5.2: For the upper edge plate, select the flat roller for the upper edge plate groove and the roller with r5 on both sides for grinding the upper edge plate. For the lower edge plate, select the roller with r3 on the inlet side of the lower edge plate, the roller with r1 on the exhaust side of the lower edge plate, and the roller with r3 on the exhaust side of the lower edge plate, and dress the grinding wheels to match the shaped surfaces of each type of roller. Step 5.3: The grinding wheels of each type are used to grind different parts of the blade, including Step 5.3.1: Use the grinding wheel with R5 on both sides of the upper edge plate in Step 5.

2. The method of removing 0.4 mm of margin for the first rough grinding, 0.4 mm of margin for the second rough grinding, 0.1 mm of margin for the semi-finishing grinding, and 0.1 mm of margin for the finishing grinding to the finished size is adopted to machine the R5-sized surface on the exhaust side of the upper edge plate of the blade. Step 5.3.2: After dressing the grinding wheel with the roller with R5 on both sides of the upper edge plate in Step 5.2, use the grinding wheel. The method of removing 0.4 mm of margin for the first rough grinding, 0.4 mm of margin for the second rough grinding, 0.1 mm of margin for the semi-finishing grinding, and 0.1 mm of margin for the finishing grinding to the finished size is adopted to machine the R5-sized surface on the inlet side of the upper edge plate of the blade. Step 5.3.3: After dressing the grinding wheel with the flat roller for the upper edge plate groove in Step 5.2, use the grinding wheel. The method of removing 0.4 mm of margin for the first rough grinding, 0.4 mm of margin for the second rough grinding, 0.1 mm of margin for the semi-finishing grinding, and 0.1 mm of margin for the finishing grinding to the finished size is adopted to machine the flat surface of the upper edge plate groove of the blade. Step 5.3.4: After dressing the grinding wheel with the flat roller for the upper edge plate groove in Step 5.2, use the grinding wheel. The method of removing 0.4 mm of margin for the first rough grinding, 0.4 mm of margin for the second rough grinding, 0.1 mm of margin for the semi-finishing grinding, and 0.1 mm of margin for the finishing grinding to the finished size is adopted to machine the outer arc surface on the exhaust side of the upper edge plate of the blade. Step 5.3.5: After grinding the grinding wheel with the R3 roller for grinding the intake edge of the lower blade plate in Step 5.2, use the grinding wheel to machine the R3 dimension surface of the intake edge of the lower blade plate in the way of rough grinding for the first time to remove a surplus of 0.4 mm, rough grinding for the second time to remove a surplus of 0.4 mm, semi-finishing grinding to remove a surplus of 0.1 mm, and finish grinding to remove a surplus of 0.1 mm to the finished dimension. Step 5.3.6: After grinding the grinding wheel with the R1 roller for grinding the exhaust edge of the lower blade plate in Step 5.2, use the grinding wheel to machine the R1 dimension surface of the exhaust edge of the lower blade plate in the way of rough grinding for the first time to remove a surplus of 0.4 mm, rough grinding for the second time to remove a surplus of 0.4 mm, semi-finishing grinding to remove a surplus of 0.1 mm, and finish grinding to remove a surplus of 0.1 mm to the finished dimension. Step 5.3.7: After grinding the grinding wheel with the flat roller for grinding the groove of the upper blade plate in Step 5.2, use the grinding wheel to machine the inner arc surface at the lower end of the lower blade plate in the way of rough grinding for the first time to remove a surplus of 0.4 mm, rough grinding for the second time to remove a surplus of 0.4 mm, semi-finishing grinding to remove a surplus of 0.1 mm, and finish grinding to remove a surplus of 0.1 mm to the finished dimension. Step 5.3.8: After grinding the grinding wheel with the R3 roller for grinding the exhaust edge of the lower blade plate in Step 5.2, use the grinding wheel to machine the R3 dimension surface of the exhaust edge of the lower blade plate in the way of rough grinding for the first time to remove a surplus of 0.4 mm, rough grinding for the second time to remove a surplus of 0.4 mm, semi-finishing grinding to remove a surplus of 0.1 mm, and finish grinding to remove a surplus of 0.1 mm to the finished dimension. Step 5.3.9: After grinding the grinding wheel with the flat roller for grinding the groove of the upper blade plate in Step 5.2, deflect the angle to machine the inner chamfer of the intake edge groove of the upper blade plate. Step 5.3.10: After grinding the grinding wheel with the flat roller for grinding the groove of the upper blade plate in Step 5.2, deflect the angle to machine the inner chamfer of the exhaust edge groove of the upper blade plate. Step 5.3.11: After grinding the grinding wheel with the flat roller for grinding the groove of the upper blade plate in Step 5.2, deflect the angle to machine the outer chamfer of the exhaust edge groove of the upper blade plate. Step 5.3.12: After grinding the grinding wheel with the flat roller for grinding the groove of the upper blade plate in Step 5.2, deflect the angle to machine the chamfer of the exhaust edge of the lower blade plate.

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