Precisely-forged blade air inlet and exhaust edge machining device and method

Abstract

The invention discloses a machining device and method for air inlet and exhaust edges of a precision forging blade. The machining device is mainly composed of an adapter plate, a bottom plate, a pressing plate, a blade basin pressing block, a blade back supporting block, an elastic supporting block and a pressing supporting block. And the air inlet and exhaust edges of the precisely-forged blade are machined in the modes of fixed blade body state milling, self-adaptive grinding and vibration finishing. The machining difficulty caused by the factors such as the blade body position degree and torsion of the precision forging blade is avoided, the problems that the precision forging blade is low in polishing percent of pass and poor in consistency caused by manual blind polishing are solved, and the machining period of parts is shortened. The problem that the air inlet and outlet edges of the precisely-forged blade are not easy to clamp in the machining process is further solved, and the problem that the air inlet and outlet edges of the precisely-forged blade are prone to being affected by the clamping force of a clamp and the cutting force of a tool to deform in the machining process is solved through the structural design attached to the curved surface of the blade and the reasonable arrangement of the pressing position.

Description

Technical Field

[0001] The invention relates to a device and a method for processing the inlet and exhaust edges of precision-forged blades of an aero-engine, belonging to the technical field of precision-forged blade processing in the production of aero-engines. Background Art

[0002] Compared with ordinary die-forged blades, aircraft engine precision-forged blades have the characteristics of high blade size accuracy and high material utilization rate. At the same time, they have better metal streamlines and metallographic structures, which can effectively improve blade performance and service life and reduce production costs.

[0003] like Figure 1 and Figure 2 As shown in the figure, the blade body profile of the precision forged blade of an aero-engine is directly formed by precision forging, but the inlet and exhaust edges are in the direction of forging flash and excess material discharge, and cannot directly reach the design size, and still have a 2mm margin. The inlet and exhaust edges of the blade body need to be processed during the machining process. Since the blade body has reached the design size, there are certain differences in the position and torsion of different blades, and it cannot be directly processed using a fixed CNC program.

[0004] At present, the steps of manual polishing of the inlet and outlet edges of blades are: first blind polishing, then three-coordinate measurement of the blades, and according to the measurement results, mark the out-of-tolerance position and the amount of out-of-tolerance on the blades with a marker, and then manually polish and repair. After polishing and repair, three-coordinate measurement is performed again until it is qualified. The time for a round of measurement, marking, and polishing is approximately 10 to 15 minutes per piece. Generally, 4 to 6 rounds of repeated measurement and polishing are required to process qualified blades. The average time for polishing the inlet and outlet edges of each blade is about 1 hour, which is particularly affected by the skill level of the polishing workers. Due to the large spatial distortion and thin relative thickness of the inlet and outlet edges of the blades (the minimum blade tip equivalent radius is less than 0.1mm), direct manual polishing is prone to large shape errors, poor consistency, and high scrap rates. In addition, the shape accuracy of the inlet and outlet edges of the blades is more important than the dimensional accuracy. Manual polishing is prone to shape accuracy errors, resulting in product scrapping. Summary of the invention

[0005] The present invention aims to provide a device and method for processing the inlet and exhaust edges of precision forged blades, so as to obtain the precise shape and dimensional accuracy of the inlet and exhaust edges on the precision forged blades, ensure the processing consistency and qualified rate of the precision forged blades, improve the processing efficiency, and solve the deformation problem during the processing.

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

[0007] A precision forged blade inlet and outlet edge processing device, comprising:

[0008] A blade basin pressing block is pressed on the blade basin profile of the precision forged blade, wherein the surface of the blade basin pressing block comprises a pressing surface, and the contour of the pressing surface is consistent with the blade basin theoretical profile of the precision forged blade;

[0009] A blade back support block for supporting the blade back profile of the precision forged blade, wherein the surface of the blade back support block comprises a support surface, and the contour of the support surface is consistent with the blade back theoretical profile of the precision forged blade;

[0010] A pressing plate, the pressing plate is connected to the blade basin pressing block and applies a force to the blade basin pressing block so that the pressing surface of the blade basin pressing block is closely attached to the blade basin profile of the precision forged blade;

[0011] Elastic support blocks, two of which are respectively arranged on the left and right sides of the blade back support block, the upper ends of the elastic support blocks are in contact with one side of the blade back of the precision forged blade, and the contact points are located on the left and right sides of the supporting surface of the blade back support block, and the height of the elastic support blocks is adjustable and has a height locking function;

[0012] The two pressing support blocks are respectively located on the left and right sides of the leaf basin pressing block, and the upper ends of the pressing support blocks are connected to the pressing plates.

[0013] As a solution, the precision forged blade inlet and exhaust edge processing device also includes an adapter plate and a base plate. The adapter plate is connected to the machine tool rotary shaft. The adapter plate includes a disc-shaped base. A support beam extends from the center of the base and along the axis of the machine tool rotary shaft. The base plate is installed on the support beam. The upper end of the base plate has an installation plane parallel to the machine tool rotary shaft, and the lower ends of the blade back support block, the elastic support block and the clamping support block are fixed on the installation plane.

[0014] As a solution, the elastic support block includes a support, a blind hole is opened at the upper end of the support, a support block is slidably connected in the blind hole, the upper end of the support block forms the upper end of the elastic support block, a spring is arranged between the lower end of the support block and the bottom of the blind hole, a threaded hole is opened on the side of the support, a locking screw is arranged in the threaded hole, and the end of the locking screw points to the support block.

[0015] A method for processing the inlet and exhaust edges of precision forged blades adopts the above-mentioned inlet and exhaust edge processing device of precision forged blades and comprises the following steps:

[0016] S1, clamp and position the precision forged blade, place a gasket on the upper end of the blade back support block, then place the precision forged blade on the gasket, press the precision forged blade from one side of the blade basin of the precision forged blade until the blade back of the precision forged blade compresses the elastic support block for a certain distance and then locks the height of the elastic support block, removes the gasket, drives the blade basin pressing block to move toward the blade basin of the precision forged blade through the pressing plate until the blade basin of the precision forged blade is pressed, and locks the position of the pressing plate;

[0017] S2, milling the inlet and outlet edges of the precision forged blades, leaving a machining allowance for subsequent grinding;

[0018] S3, grinding the inlet and exhaust edges of the precision forged blades, using an adaptive processing method to compare the actual model with the theoretical model to obtain a new benchmark and plan a new grinding trajectory, and completing the grinding of the inlet and exhaust edges of the precision forged blades according to the new grinding trajectory;

[0019] S4, vibration finishing, uses a vibration finishing machine to perform vibration finishing on the precision forged blades after S3 grinding, and changes the small pointed heads of the inlet and exhaust edges of the precision forged blades into round heads.

[0020] Furthermore, in S1, the thickness of the gasket is such that the precision forged blade located between the two elastic support blocks only generates elastic deformation when being pressed.

[0021] Furthermore, in S2, a CNC milling program is used, and the air intake side is milled first, and then the exhaust side is milled.

[0022] Further, the S3 specifically includes the following steps:

[0023] S31, measuring the actual margin of the inlet and outlet edges of the precision forged blade to obtain the spatial posture and actual shape of the precision forged blade;

[0024] S32, benchmark registration, using ICP algorithm to perform spatial registration on the precision forged blade and the measurement data in S31, to obtain the optimal blade space coordinate system of the precision forged blade and adjust the blade space posture;

[0025] S33, model reconstruction, in the optimal coordinate system obtained in S32, based on the theoretical digital model of the precision forging blade and the measurement data in S31, reconstruct the adaptive processing model of the inlet and exhaust edges of the precision forging blade, and establish a parameter mapping relationship between the theoretical model of the precision forging blade and the reconstructed model;

[0026] S34, adaptive grinding processing, adaptively adjusting the grinding trajectory according to the parameter mapping relationship in S33, and adaptively grinding the inlet and outlet edges of the precision forged blades.

[0027] As an option, in S31, an optical scanning detection method is used to measure the actual margin of the precision forged blade, and the measurement position includes the margin of the intake edge and exhaust edge of the precision forged blade, and the margin within a certain distance from the leading edge and the trailing edge of the precision forged blade.

[0028] As an option, in S34, a flexible fiber grinding wheel is used for grinding, the grinding wheel diameter is Φ300 mm, the grinding depth is 3 mm to 5 mm, and the grinding deflection angle is ±20°.

[0029] As an option:

[0030] In S1, the gasket is a copper sheet, and the thickness of the copper sheet is 0.03 mm;

[0031] In S2, the reserved machining allowance is 0.3 mm to 0.4 mm, the milling tool is D6R3, the milling spindle speed is 2500 r / min, and the feed rate is 500 mm / min.

[0032] Compared with the prior art, the present invention has the following characteristics:

[0033] (1) The present invention provides a new processing method for the inlet and exhaust edges of precision forged blades. It no longer uses the traditional manual blind polishing process, but adopts the method of "fixed blade state milling + adaptive grinding + vibration finishing". It avoids the processing difficulties caused by factors such as the position and torsion of the precision forged blades, solves the problems of low polishing pass rate and poor consistency of precision forged blades caused by manual blind polishing, and shortens the processing cycle of parts.

[0034] (2) The present invention designs a special processing device for milling the inlet and outlet edges of precision forged blades, which solves the problem that the inlet and outlet edges of precision forged blades involved in the present invention are difficult to clamp during the processing. The special processing device solves the problem that the inlet and outlet edges of precision forged blades are easily deformed by the clamping force of the fixture and the cutting force of the tool during the processing through a structural design that fits the curved surface of the part and a reasonable arrangement of the clamping position. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the parts structure of the precision forged blade in the present invention;

[0036] Figure 2 It is a schematic diagram of the blade profile of the precision forged blade in the present invention;

[0037] Figure 3 It is a three-dimensional diagram of the precision forging blade inlet and exhaust edge processing device designed by the present invention;

[0038] Figure 4 This is a process flow chart of the adaptive grinding of the intake and exhaust edges of precision forged blades in the present invention;

[0039] Figure 5 Schematic diagram of the adaptive grinding processing state of the inlet and outlet edges of the precision forged blade in the present invention;

[0040] In the figure, 1-adapter plate, 2-bottom plate, 3-pressing plate, 4-blade basin pressing block, 5-blade back support block, 6-elastic support block, 7-pressing support block. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with specific embodiments, but it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0042] Figure 3 The device for processing the inlet and exhaust edges of precision forged blades designed in the present invention is shown, which is mainly composed of an adapter plate 1, a base plate 2, a clamping plate 3, a blade basin clamping block 4, a blade back support block 5, an elastic support block 6 and a clamping support block 7.

[0043] The processing ideas for the precision forged blade inlet and outlet edges in the present invention are as follows:

[0044] (1) Manufacturing the blade basin pressing block 4: designing the structure of the blade basin pressing block 4 according to the blade basin theoretical profile of the precision forged blade, and manufacturing the blade basin pressing block 4 having the same blade basin theoretical profile as the precision forged blade;

[0045] (2) Manufacturing the blade back support block 5: designing the structure of the blade back support block 5 according to the blade back theoretical profile of the precision forged blade, and manufacturing the blade back support block 5 having the same blade back theoretical profile as the precision forged blade;

[0046] (3) Clamping and positioning of the rough material (precision forging blade rough material): Place a 0.03 mm thick copper sheet on the blade back support block 5, and lock the elastic support block 6 after the blade back direction of the precision forging blade is in contact with the blade back support block 5. Then remove the copper sheet and press the blade basin pressing block 4 to ensure that the precision forging blades with different position and torsion are in the same state after clamping;

[0047] (4) Milling the intake and exhaust edges: Use a computer and UG programming software to generate a fixed CNC machining program to machine the intake and exhaust edges, leaving a margin of 0.3 mm to 0.4 mm, and reserve the machining margin for subsequent grinding;

[0048] (5) Grinding the intake and exhaust edges: Use an optical scanning measuring machine to detect and calculate the allowance of the intake and exhaust edges to obtain the actual allowance; use an adaptive processing method to compare the actual model with the theoretical model to obtain a new benchmark and plan the grinding trajectory (secondary correction), and complete the automated grinding process according to the new grinding trajectory;

[0049] (6) Blade vibration finishing: A vibration finishing machine is used to perform vibration finishing on the blades after grinding. The vibration finishing processing time is 30 minutes to 50 minutes.

[0050] Specifically, the method for processing the intake and exhaust edges of precision forged blades includes the following steps:

[0051] Milling and machining of the fine forged blade inlet and exhaust edges:

[0052] Step S1: Making the blade basin pressing block 4: machining the blade basin pressing block 4 according to the theoretical profile of the blade basin of the precision forged blade, ensuring that the blade basin is in a surface-fitting state with the blade when pressed, and the blade basin is pressed evenly;

[0053] Step S2: Making the blade back support block 5: The blade back support block 5 is processed according to the theoretical profile of the blade back of the precision forged blade to ensure that the blade back is in a surface-to-surface state with the blade when supporting it, and the blade back support is evenly stressed.

[0054] Step S3: clamping and positioning of the rough material (fine forging blade rough material): before the fine forging blade is processed, the processing device needs to be fixed to the rotating shaft of the machine tool through the adapter plate 1 and the base plate 2. Before the fine forging blade is clamped, a copper sheet with a thickness of about 0.03mm is placed on the blade back support block 5, and then the fine forging blade is placed on the copper sheet. After pressing the blade with hands or other tools, the height position of the elastic support blocks 6 on both sides is locked, and then the copper sheet is withdrawn; the blade basin of the fine forging blade is pressed with the blade basin clamping block 4, and the clamping plate 3 is locked (the clamping plate 3 and the clamping plate support block 7 are threadedly connected, and the height position of the clamping plate 3 on the clamping support block 7 is locked by a nut). At this time, since there is a gap of 0.03mm between the blade body of the fine forging blade and the blade back support block 5, the fine forging blade fits with the blade back support block 5 through elastic deformation during clamping, which can ensure that the blade body of the fine forging blade with differences in position, torsion, etc. is consistent after the processing device is clamped.

[0055] Step S4: milling the intake and exhaust edges of the precision forged blades: using a computer and UG programming software to generate a fixed CNC milling program (the fixed CNC milling program here is relative to the subsequent adaptive grinding), and processing the intake and exhaust edges. The processing process is divided into two stages, the first stage is milling the intake edge, and the second stage is milling the exhaust edge. During cutting, the tool D6R3 is selected, the spindle speed is 2500r / min, the feed rate F is set to 500mm / min, and the intake and exhaust edges are left with a margin of 0.3mm-0.4mm, and the reserved processing margin is used for subsequent grinding;

[0056] The above method of milling the inlet and exhaust edges of the fixed precision forged blade body can largely solve the processing consistency problem caused by differences in blade body position, torsion and other factors. However, it may be affected by factors such as blade deformation and clamping error during the processing, and there is a small processing error. Therefore, adaptive grinding is used for secondary correction to ensure that the inlet and exhaust edges of the precision forged blades are processed with high precision, high consistency and high efficiency. The adaptive grinding process is as follows: Figure 4 As shown, the following processing steps are included:

[0057] Adaptive grinding of forged blade inlet and exhaust edges:

[0058] Step S5: Blade inlet and outlet margin measurement: Use optical scanning detection and other methods to detect and calculate the actual margin of the precision forged blade (including the inlet and outlet edges and the blade body margin 1mm from the leading and trailing edges) to obtain the spatial posture and actual shape of the blade;

[0059] Step S6: Reference registration: Use ICP (Iterative Closest Point) registration algorithm to perform spatial registration on the blade and the measurement data to obtain the optimal coordinate system of the blade space and adjust the blade space posture; for the specific process, please refer to "Zhai Fugang, Zhao Zhi, Cai Zhenhui, et al. Blank registration method based on blade cross-sectional characteristic parameters [J]. Electrical Machining and Die, 2023, (S1): 13-19+54." or any existing technology about ICP algorithm registration;

[0060] Step S7: Model reconstruction: In the optimal coordinate system determined in S6, based on the blade theoretical digital model and the measured data, the blade inlet and exhaust edge adaptive processing model is reconstructed, and the parameter mapping relationship between the blade theoretical model and the reconstructed model is established; for the specific process, please refer to "Feng Yazhou, Ren Junxue, Liang Yongshou, et al. Multi-objective constraint precision forging blade geometry reconstruction optimization algorithm [J]. Acta Aeronautica Sinica, 2018, 39(07): 228-238." or any existing technology on blade processing model reconstruction or any existing technology on blade adaptive processing;

[0061] Step S8: Adaptive grinding: Adaptively adjust the grinding trajectory according to the parameter mapping relationship, and adaptively process the blade intake and exhaust edges (the tolerance is ±0.035mm on the length of 1mm from the leading and trailing edges). The wheel used for processing is a flexible fiber grinding wheel with a diameter of Φ300mm. The blade grinding depth is 3mm-5mm, the grinding deflection angle is ±20°, and the pitch angle generally depends on the edge plate. The schematic diagram of the adaptive grinding process is shown in FIG. Figure 5 shown.

[0062] Step S9: vibration finishing of blades: a vibration finishing machine is used to perform vibration finishing on the fine forged blades after grinding, so as to change the small pointed heads on the inlet and outlet edges of the fine forged blades into round heads. The vibration finishing processing time is 30 minutes to 50 minutes.

[0063] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. Although the illustrative specific embodiments of the present invention are described above to facilitate the understanding of the present invention by the technical personnel in the field, it should be clear that the present invention is not limited to the scope of the specific embodiments. For ordinary technicians in the field of this technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A precision forging blade inlet and exhaust edge processing device, characterized in that: include: A blade basin pressing block (4) is pressed onto the blade basin profile of the precision forged blade, wherein the surface of the blade basin pressing block (4) comprises a pressing surface, and the contour of the pressing surface is consistent with the blade basin theoretical profile of the precision forged blade; A blade back support block (5) for supporting the blade back profile of a precision forged blade, wherein the surface of the blade back support block (5) comprises a support surface, the contour of the support surface being consistent with the blade back theoretical profile of the precision forged blade; A pressing plate (3), wherein the pressing plate (3) is connected to a blade basin pressing block (4) and applies a force to the blade basin pressing block (4) so ​​that a pressing surface of the blade basin pressing block (4) is closely attached to a blade basin profile of the precision forged blade; An elastic support block (6), wherein two elastic support blocks (6) are respectively arranged on the left and right sides of the blade back support block (5), the upper ends of the elastic support blocks (6) are in contact with one side of the blade back of the precision forged blade, and the contact points are located on the left and right sides of the support surface of the blade back support block (5), and the height of the elastic support blocks (6) is adjustable and has a height locking function; The two pressing support blocks (7) are respectively located on the left and right sides of the leaf basin pressing block (4), and the upper ends of the pressing support blocks (7) are connected to the pressing plate (3).

2. A precision forging blade inlet and exhaust edge processing device according to claim 1, characterized in that: It also comprises an adapter plate (1) and a base plate (2), wherein the adapter plate (1) is connected to the rotary shaft of the machine tool, the adapter plate (1) comprises a disc-shaped base, a support beam extends from the center of the base and along the axis direction of the rotary shaft of the machine tool, the base plate (2) is mounted on the support beam, the upper end of the base plate (2) is provided with a mounting plane parallel to the rotary shaft of the machine tool, and the lower ends of the blade back support block (5), the elastic support block (6) and the clamping support block (7) are fixed on the mounting plane.

3. The device for processing the inlet and exhaust edges of precision forged blades according to claim 1, characterized in that: The elastic support block (6) comprises a support, a blind hole is formed at the upper end of the support, a support block is slidably connected in the blind hole, the upper end of the support block forms the upper end of the elastic support block (6), a spring is arranged between the lower end of the support block and the bottom of the blind hole, a threaded hole is formed on the side of the support, a locking screw is arranged in the threaded hole, and the end of the locking screw points to the support block.

4. A method for processing the intake and exhaust edges of precision forged blades, characterized in that: The device for processing the inlet and exhaust edges of precision forged blades according to claim 1 is used, and includes the following steps: S1, clamping and positioning the precision forged blade, placing a gasket on the upper end of the blade back support block (5), then placing the precision forged blade on the gasket, pressing the precision forged blade from one side of the blade basin of the precision forged blade until the blade back of the precision forged blade compresses the elastic support block (6) for a certain distance, then locking the height of the elastic support block (6), taking out the gasket, driving the blade basin pressing block (4) to move toward the blade basin of the precision forged blade through the pressing plate (3) until the blade basin of the precision forged blade is pressed, and locking the position of the pressing plate (3); S2, milling the inlet and outlet edges of the precision forged blades, leaving a machining allowance for subsequent grinding; S3, grinding the inlet and exhaust edges of the precision forged blades, using an adaptive processing method to compare the actual model with the theoretical model to obtain a new benchmark and plan a new grinding trajectory, and completing the grinding of the inlet and exhaust edges of the precision forged blades according to the new grinding trajectory; S4, vibration finishing, uses a vibration finishing machine to perform vibration finishing on the precision forged blades after S3 grinding, and changes the small pointed heads of the inlet and exhaust edges of the precision forged blades into round heads.

5. A method for processing the intake and exhaust edges of precision forged blades according to claim 4, characterized in that: In S1, the thickness of the gasket is such that the precision forged blade located between the two elastic support blocks (6) only undergoes elastic deformation when pressed.

6. A method for processing the intake and exhaust edges of precision forged blades according to claim 4, characterized in that: In S2, a numerical control milling program is used, and the air intake side is milled first, and then the exhaust side is milled.

7. A method for processing the intake and exhaust edges of precision forged blades according to claim 4, characterized in that: The S3 specifically includes the following steps: S31, measuring the actual margin of the inlet and outlet edges of the precision forged blade to obtain the spatial posture and actual shape of the precision forged blade; S32, benchmark registration, using ICP algorithm to perform spatial registration on the precision forged blade and the measurement data in S31, to obtain the optimal blade space coordinate system of the precision forged blade and adjust the blade space posture; S33, model reconstruction, in the optimal coordinate system obtained in S32, based on the theoretical digital model of the precision forging blade and the measurement data in S31, reconstruct the adaptive processing model of the inlet and exhaust edges of the precision forging blade, and establish a parameter mapping relationship between the theoretical model of the precision forging blade and the reconstructed model; S34, adaptive grinding processing, adaptively adjusting the grinding trajectory according to the parameter mapping relationship in S33, and adaptively grinding the inlet and outlet edges of the precision forged blades.

8. A method for processing the intake and exhaust edges of precision forged blades according to claim 7, characterized in that: In S31, an optical scanning detection method is used to measure the actual margin of the precision forged blade, and the measurement position includes the margin of the air inlet edge and the exhaust edge of the precision forged blade, and the margin within a distance from the leading edge and the trailing edge of the precision forged blade.

9. A method for processing the intake and exhaust edges of precision forged blades according to claim 7, characterized in that: In the step S34, a flexible fiber grinding wheel is used for grinding, the grinding wheel diameter is Φ300 mm, the grinding depth is 3 mm to 5 mm, and the grinding deflection angle is ±20°.

10. A method for processing the intake and exhaust edges of precision forged blades according to claim 4, characterized in that: In S1, the gasket is a copper sheet, and the thickness of the copper sheet is 0.03 mm; In S2, the reserved machining allowance is 0.3 mm to 0.4 mm, the milling tool is D6R3, the milling spindle speed is 2500 r / min, and the feed rate is 500 mm / min.

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