Aero-engine composite material blade positioning machining method based on reverse design

Abstract

The invention discloses an aero-engine composite material blade positioning and processing method based on reverse design. The method comprises the following steps: step (A), blade scanning and profile fitting; step (B), reversely designing a blade machining tool; (C), a tool positioning molded surface of the blade machining tool is machined; (D), the blade to be machined is positioned; and (E) processing the blade. According to the method, fitting is conducted on the basis of the actually-formed composite material blade, the scanning mathematical model and the blank mathematical model, precise positioning is conducted on the blade on the basis of the reversely-designed tool profile, the positioning precision is guaranteed, the positioning efficiency is improved, clamping deformation cannot be caused in the blade positioning and clamping process, and good application prospects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of composite material manufacturing, and in particular to a positioning processing method for composite material blades of an aero-engine based on reverse design. Background Art

[0002] At present, the blades of aircraft engines are connected to the engine disk through the tenons on the tenon root. The installation posture and accuracy of the blade will directly affect the operating performance of the engine. Therefore, the machining accuracy of the blade tenon root becomes particularly critical and is also a key technology for blade processing. The blade shape and tenon root position of the traditional blade made of metal materials are all processed and formed as a whole by CNC machine tools, which can ensure the adaptability of the blade shape and tenon root processing.

[0003] However, for blades made of composite materials, the accuracy of their blade shape is guaranteed by the molding tooling and process, but the position of their tenon cannot meet the accuracy requirements through direct molding. Therefore, secondary processing is required to ensure the overall accuracy of the composite blade through molding with allowance. However, since the blade shape and tenon of the composite blade are formed by two different processing methods, there is a great difficulty in the reference transfer path, and it is impossible to ensure that the tenon processing matches the actual blade shape. Moreover, the current CNC machine tool processing of composite blades cannot ensure that the blade positioning position is consistent with the theoretical digital model position, resulting in processing errors. Therefore, how to overcome the consistency of the blade shape and tenon processing of composite blades is a problem that urgently needs to be solved. Summary of the invention

[0004] The technical problem solved by the present invention is to overcome the problem that the existing composite blades cannot ensure that the tenon processing matches the actual blade shape. The present invention is based on the actual formed composite blade, scans the digital model and the raw material digital model for fitting, and based on the reverse design of the tooling surface, accurately positions the blade, ensures the positioning accuracy, improves the positioning efficiency, and does not cause clamping deformation during the blade positioning and clamping process, and has good application prospects.

[0005] In order to solve the above technical problems and achieve the above objectives, the technical solution adopted by the present invention is: A method for positioning and processing composite material blades of an aero-engine based on reverse design, characterized in that it comprises the following steps: Step (A), blade scanning and profile fitting: Scan the blade profile of the blade to be processed, and perform the best fit between the scanning result and the theoretical rough material digital model to obtain the blade profile fitting result after the blade profile and the digital model are combined; Step (B), reverse design of blade machining tooling: According to the blade surface fitting result, the actual blade point cloud data is obtained, the point cloud results of the lower adjacent area are intercepted to perform reverse tooling surface, and the tooling positioning surface of the blade machining tooling is obtained by reverse fitting data; Step (C), tooling positioning surface processing of blade machining tooling: The blade machining tooling comprises a front plate, a rear plate and a base, wherein the front plate plays a positioning role and the rear plate plays a clamping role. According to step (B), a tooling positioning profile of the blade machining tooling is obtained, and the tooling positioning profile is actually processed between the front plate and the rear plate; Step (D), positioning the blade to be processed: The blade to be processed is positioned and clamped on the blade machining tooling, and the position of the blade to be processed is detected by using 3D optical detection equipment to ensure that the actual position of the blade to be processed is the same as the position of the blade profile fitting result. If they are not the same, return to step (C) to adjust the tooling positioning profile processing until the actual position of the blade to be processed is the same as the position of the blade profile fitting result; Step (E), processing blades: Establish the machine tool processing reference according to the reference hole of the blade machining tooling, and process the blade according to the theoretical surface.

[0006] Preferably, step (A), blade scanning and profile fitting: scanning the blade profile of the blade to be processed, performing optimal fitting between the scanning result and the theoretical rough material digital model, and obtaining the blade profile fitting result after the blade profile is combined with the digital model, specifically comprises the following steps: (A1), using a 3D scanner to scan the blade to be processed after forming, the blade to be processed is a composite blade raw material, and obtain the actual surface scanning data of the composite blade, that is, the blade profile of the blade to be processed, (A2) In the PolyWoks measurement software, the 3D point cloud of the actual surface scanning data of the composite blade is optimally fitted with the theoretical rough material digital model of the blade to obtain the blade surface fitting result after the blade surface and the digital model are combined.

[0007] Preferably, (A1), a 3D scanner is used to scan the blade to be processed after forming. The specific scanning requirements are that the scanning should be carried out when the blade to be processed is in a free state. During the scanning, the tenon root margin area should be supported to prevent the blade to be processed from deforming, and the complete surface of the blade should be scanned.

[0008] Preferably, step (B), reverse design of blade machining tooling: according to the blade profile fitting result, actual blade point cloud data is obtained, the point cloud result of the lower adjacent area is intercepted to reverse the tooling profile, and the tooling positioning profile of the blade machining tooling is obtained by reverse fitting data, which specifically includes the following steps: (B1), since the tenon root is the machine tool processing area, the blade profile surface part of the blade needs to be located, the scanning data of the blade profile fitting result is imported into the 3D design software CATIA, and the actual blade point cloud data is trimmed and extracted through the Digtized Shape Editor module, and divided into six positioning surfaces; (B2), using CATIA Quick Suface Reconstruction module, the extracted six positioning surfaces are reverse processed into the tooling positioning surfaces of the blade machining tooling; (B3) Measure the deviation between the actual blade point cloud data and the tooling positioning surface, and offset the reverse surface corresponding to the raised area of ​​the point cloud outward to prevent the raised area of ​​the blade from interfering with the actual tooling. The offset amount of the reverse surface corresponding to the raised area of ​​the point cloud outward is the maximum raised value of the raised area of ​​the blade.

[0009] Preferably, step (D), positioning the blade to be processed: ensuring that the actual position of the blade to be processed is the same as the position of the blade profile fitting result, and the theoretical position deviation is less than 0.05 mm.

[0010] Preferably, step (D) positions the blade to be processed: the blade to be processed is positioned and clamped on the blade machining tooling, and a 3D optical detection device is used to detect the position of the blade to be processed. The specific process is that after positioning and clamping, a reference is established with a reference surface and a reference hole of the blade machining tooling, and the blade profile is detected.

[0011] Preferably, step (E), processing the blade: establishing a machine tool processing reference according to the reference hole of the blade machining tooling, and processing the blade according to the theoretical surface. The specific process is 2mm allowance rough processing, 0.5mm allowance semi-finishing, and net size finishing. After each processing step is completed, the surface of the tenon root of the blade is inspected, and the processing allowance is adjusted according to the inspection result to ensure the processing accuracy.

[0012] Preferably, the specific process of adjusting the machining allowance according to the detection results is to compare the machined blade profile with the theoretical profile, analyze the top surface, left and right end surfaces, front and back surfaces, compare the measured allowance of each machined surface with the theoretical allowance, and adjust the machining program to compensate for the allowance deviation.

[0013] The beneficial effects of the present invention are as follows: the reverse design-based positioning processing method for composite blades of an aero-engine according to the present invention is based on the reverse design of the formed blade profile, and the blade profile fitting result after the blade profile and the numerical simulation are obtained, and the actual blade point cloud data is obtained according to the blade profile fitting result, and the point cloud result of the lower adjacent area is intercepted to perform the reverse tooling profile, and the tooling positioning profile of the blade machining tooling is obtained through the reverse fitting data, thereby ensuring the positioning accuracy of the composite blades of the aero-engine; the positioning efficiency is also improved, because the tooling positioning profile of the machining tooling is completely matched with the blade profile of the composite blades of the aero-engine, there is no need to adjust the blade position, thereby improving the blade positioning processing efficiency and facilitating the operation; moreover, the tooling positioning profile of the machining tooling is completely matched with the blade profile of the composite blades of the aero-engine, and no clamping deformation will be caused during the blade positioning and clamping process, thereby improving the processing effect of the composite blades of the aero-engine.

[0014] The present invention is based on an actually formed composite material blade, and scans a digital model and a raw material digital model for fitting. Based on a reverse design of a tooling surface, the blade is precisely positioned, thereby ensuring positioning accuracy and improving positioning efficiency. During the blade positioning and clamping process, no clamping deformation will be caused, and the invention has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the process of positioning processing method of composite blades of aero-engine based on reverse design; Figure 2 This is a comparison chart of the digital model of the composite blade raw material and the net size of the blade parts; Figure 3 It is a schematic diagram of the blade profile fitting result after the blade profile is combined with the numerical simulation; Figure 4 It is a structural schematic diagram of the tooling positioning surface of the blade machining tooling; Figure 5 It is an overall schematic diagram after positioning the blade to be processed. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] like Figure 1 As shown, the reverse design-based positioning processing method for composite material blades of an aero-engine of the present invention comprises the following steps: Step (A), blade scanning and profile fitting: Scan the blade profile of the blade to be processed, and perform the best fit between the scanning result and the theoretical rough material digital model to obtain the blade profile fitting result after the blade profile and the digital model are combined; Step (B), reverse design of blade machining tooling: According to the blade surface fitting result, the actual blade point cloud data is obtained, the point cloud results of the lower adjacent area are intercepted to perform reverse tooling surface, and the tooling positioning surface of the blade machining tooling is obtained by reverse fitting data; Step (C), tooling positioning surface processing of blade machining tooling: The blade machining tooling comprises a front plate, a rear plate and a base, wherein the front plate plays a positioning role and the rear plate plays a clamping role. According to step (B), a tooling positioning profile of the blade machining tooling is obtained, and the tooling positioning profile is actually processed between the front plate and the rear plate; Step (D), positioning the blade to be processed: The blade to be processed is positioned and clamped on the blade machining tooling, and the position of the blade to be processed is detected by using 3D optical detection equipment to ensure that the actual position of the blade to be processed is the same as the position of the blade profile fitting result. If they are not the same, return to step (C) to adjust the tooling positioning profile processing until the actual position of the blade to be processed is the same as the position of the blade profile fitting result. Here, the actual position of the blade to be processed is ensured to be the same as the position of the blade profile fitting result, and the theoretical position deviation is less than 0.05mm; Step (E), processing blades: Establish the machine tool processing reference according to the reference hole of the blade machining tooling, and process the blade according to the theoretical surface.

[0018] The following is a method for positioning and processing composite material blades of an aero-engine based on reverse design according to the present invention. Figure 2-5 Here is a detailed introduction to the implementation process: Step (A), blade scanning and profile fitting: scanning the blade profile of the blade to be processed, performing the best fit between the scanning result and the theoretical rough material digital model, and obtaining the blade profile fitting result after the blade profile and the digital model are combined, which specifically includes the following steps: (A1) A 3D scanner is used to scan the blade to be processed after forming. The blade to be processed is a composite blade rough material, and the actual surface scanning data of the composite blade is obtained, that is, the blade profile of the blade to be processed. The specific scanning requirements are that the blade to be processed should be scanned in a free state, and the tenon root margin area should be supported during scanning to prevent the blade to be processed from deforming, and the complete surface of the blade should be scanned; the digital model of the composite blade rough material is compared with the net size of the blade part. Figure 2 As shown; (A2) In the PolyWoks measurement software, the 3D point cloud of the actual surface scan data of the composite blade is optimally fitted with the theoretical rough material digital model of the blade to obtain the blade surface fitting result after the blade surface and the digital model are combined. The schematic diagram of the fitting result is shown in the figure. Figure 3 As shown; Step (B), reverse design of blade machining tooling: according to the blade profile fitting result, the actual blade point cloud data is obtained, the point cloud result of the lower adjacent area is intercepted to reverse the tooling profile, and the tooling positioning profile of the blade machining tooling is obtained by reverse fitting data, which specifically includes the following steps: (B1), since the tenon root is the machine tool processing area, the blade profile surface part of the blade needs to be located, the scanning data of the blade profile fitting result is imported into the 3D design software CATIA, and the actual blade point cloud data is trimmed and extracted through the Digtized Shape Editor module, and divided into six positioning surfaces; (B2), using CATIA Quick Suface Reconstruction module, the extracted six positioning surfaces are reverse processed into the tooling positioning surfaces of the blade machining tooling; (B3), measuring the deviation between the actual blade point cloud data and the tooling positioning surface, and offsetting the reverse surface corresponding to the raised area of ​​the point cloud outward to prevent the raised area of ​​the blade from interfering with the actual tooling, wherein the offset amount of the reverse surface corresponding to the raised area of ​​the point cloud outward is the maximum raised value of the raised area of ​​the blade; Step (C), tooling positioning surface processing of blade machining tooling: The blade machining tooling includes front and rear clamping plates and a base. The front clamping plate plays a positioning role, and the rear clamping plate plays a clamping role. According to step (B), the tooling positioning profile of the blade machining tooling is obtained, and the tooling positioning profile is actually processed between the front and rear clamping plates. The specific schematic diagram is as follows Figure 4 As shown; Step (D), positioning the blade to be processed: positioning and clamping the blade to be processed on the blade machining tooling, and using 3D optical detection equipment to detect the position of the blade to be processed. The specific process is that after positioning and clamping, the reference surface and reference hole of the blade machining tooling are used to establish a reference, and the blade profile is detected. The overall schematic diagram after positioning the blade to be processed is shown in Figure 5. The tool positioning profile of the machining tooling is completely matched with the blade profile of the aircraft engine composite material blade. During the blade positioning and clamping process, no clamping deformation will be caused, thereby improving the processing effect of the aircraft engine composite material blade, and preventing deformation caused by the mismatch between the blade to be processed and the blade machining tooling; Step (E), processing the blade: establish the machine tool processing reference according to the reference hole of the blade machining tooling, and process the blade according to the theoretical profile, specifically, 2mm allowance rough processing, 0.5mm allowance semi-finishing, and net size finishing. After each processing step, the tenon root of the blade is inspected, and the processing allowance is adjusted according to the inspection results. The processed blade profile is compared with the theoretical profile, and the top surface, left and right end surfaces, front and back surfaces are analyzed. The measured allowance of each processing surface is compared with the theoretical allowance, and the processing program is adjusted to compensate for the allowance deviation to ensure the processing accuracy. For example, in an implementation process: after rough processing with a 2mm allowance, the measured top surface allowance is 2.1mm. When processing with a 0.5mm allowance, the processing program allowance needs to be set to 0.4mm for processing.

[0019] In summary, the reverse design-based positioning processing method for composite blades of an aero-engine is based on the reverse design of the formed blade profile, and the blade profile fitting result after the blade profile and the numerical simulation are obtained. According to the blade profile fitting result, the actual blade point cloud data is obtained, the point cloud result of the lower adjacent area is intercepted to perform the reverse tooling profile, and the tooling positioning profile of the blade machining tooling is obtained through the reverse fitting data, thereby ensuring the positioning accuracy of the composite blades of the aero-engine; the positioning efficiency is also improved, because the tooling positioning profile of the machining tooling is completely matched with the blade profile of the composite blades of the aero-engine, there is no need to adjust the blade position, thereby improving the blade positioning processing efficiency and facilitating the operation; moreover, the tooling positioning profile of the machining tooling is completely matched with the blade profile of the composite blades of the aero-engine, and no clamping deformation will be caused during the blade positioning and clamping process, thereby improving the processing effect of the composite blades of the aero-engine. Based on the actual formed composite material blade, the scanned digital model and the raw material digital model are fitted, and the blade is precisely positioned based on the reverse design of the tooling surface, which ensures the positioning accuracy and improves the positioning efficiency. It will not cause clamping deformation during the blade positioning and clamping process, and has good application prospects.

[0020] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for positioning and processing composite material blades of an aero-engine based on reverse design, characterized in that: The following steps are included: Step (A), blade scanning and profile fitting: Scan the blade profile of the blade to be processed, and perform the best fit between the scanning result and the theoretical rough material digital model to obtain the blade profile fitting result after the blade profile and the digital model are combined; Step (B), reverse design of blade machining tooling: According to the blade surface fitting result, the actual blade point cloud data is obtained, the point cloud results of the lower adjacent area are intercepted to perform reverse tooling surface, and the tooling positioning surface of the blade machining tooling is obtained by reverse fitting data; Step (C), tooling positioning surface processing of blade machining tooling: The blade machining tooling comprises a front plate, a rear plate and a base, wherein the front plate plays a positioning role and the rear plate plays a clamping role. According to step (B), a tooling positioning profile of the blade machining tooling is obtained, and the tooling positioning profile is actually processed between the front plate and the rear plate; Step (D), positioning the blade to be processed: The blade to be processed is positioned and clamped on the blade machining tooling, and the position of the blade to be processed is detected by using 3D optical detection equipment to ensure that the actual position of the blade to be processed is the same as the position of the blade profile fitting result. If they are not the same, return to step (C) to adjust the tooling positioning profile processing until the actual position of the blade to be processed is the same as the position of the blade profile fitting result; Step (E), processing blades: Establish the machine tool processing reference according to the reference hole of the blade machining tooling, and process the blade according to the theoretical surface.

2. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 1, characterized in that: Step (A), blade scanning and profile fitting: scanning the blade profile of the blade to be processed, performing the best fit between the scanning result and the theoretical rough material digital model, and obtaining the blade profile fitting result after the blade profile and the digital model are combined, which specifically includes the following steps: (A1), using a 3D scanner to scan the blade to be processed after forming, the blade to be processed is a composite blade raw material, and obtain the actual surface scanning data of the composite blade, that is, the blade profile of the blade to be processed, (A2) In the PolyWoks measurement software, the 3D point cloud of the actual surface scanning data of the composite blade is optimally fitted with the theoretical rough material digital model of the blade to obtain the blade surface fitting result after the blade surface and the digital model are combined.

3. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 2 is characterized in that: (A1) Use a 3D scanner to scan the blade to be processed after forming. The specific scanning requirements are that the blade to be processed should be scanned in a free state. The tenon root margin area should be supported during scanning to prevent the blade from being deformed and scan the complete surface of the blade.

4. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 1, characterized in that: Step (B), reverse design of blade machining tooling: according to the blade profile fitting result, the actual blade point cloud data is obtained, the point cloud result of the lower adjacent area is intercepted to reverse the tooling profile, and the tooling positioning profile of the blade machining tooling is obtained by reverse fitting data, which specifically includes the following steps: (B1), since the tenon root is the machine tool processing area, the blade profile surface part of the blade needs to be located, the scanning data of the blade profile fitting result is imported into the 3D design software CATIA, and the actual blade point cloud data is trimmed and extracted through the Digtized Shape Editor module, and divided into six positioning surfaces; (B2), using CATIA Quick Suface Reconstruction module, the extracted six positioning surfaces are reverse processed into the tooling positioning surfaces of the blade machining tooling; (B3) Measure the deviation between the actual blade point cloud data and the tooling positioning surface, and offset the reverse surface corresponding to the raised area of ​​the point cloud outward to prevent the raised area of ​​the blade from interfering with the actual tooling. The offset amount of the reverse surface corresponding to the raised area of ​​the point cloud outward is the maximum raised value of the raised area of ​​the blade.

5. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 1, characterized in that: Step (D), positioning the blade to be processed: ensuring that the actual position of the blade to be processed is the same as the position of the blade profile fitting result, and the theoretical position deviation is less than 0.05 mm.

6. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 1, characterized in that: Step (D), positioning the blade to be processed: the blade to be processed is positioned and clamped on the blade machining tooling, and the position of the blade to be processed is detected using 3D optical detection equipment. The specific process is that after positioning and clamping, a reference is established with the reference surface and reference hole of the blade machining tooling to detect the blade profile.

7. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 1, characterized in that: Step (E), processing the blade: establish the machine tool processing reference according to the reference hole of the blade machining tooling, and process the blade according to the theoretical profile. The specific process is 2mm allowance rough processing, 0.5mm allowance semi-finishing, and net size finishing. After each processing step, the blade's tenon root is inspected, and the processing allowance is adjusted according to the inspection result to ensure the processing accuracy.

8. The method for positioning and processing composite material blades of an aero-engine based on reverse design according to claim 7, characterized in that: The specific process of adjusting the machining allowance according to the test results is to compare the machined blade profile with the theoretical profile, analyze the top surface, left and right end surfaces, front and back surfaces, compare the measured allowance of each machined surface with the theoretical allowance, and adjust the machining program to compensate for the allowance deviation.

Images