Blade repair forming planning method for blisk of aero-engine

Abstract

The application discloses a kind of aero-engine blisk blade repair forming planning methods, to solve the problems of existing blade repair path planning method being imperfect, low degree of automation, poor repair forming quality, the application includes:1. damage identification is carried out using three-dimensional scanner;2. the extraction of camber surface in repair area;3. camber line path planning, deposition parameter setting, welding gun posture planning;4. wire feeding direction control, robot repair path simulation;5. deposition height detection is carried out using displacement sensor.By the repair forming planning method of the application, the automatic repair of the blade can be simply and high-quality realized, the redundant and poor-targeted path planning process of commercial software is avoided, the burden of operator is reduced, and a new forming approach is provided for blisk blade repair.The application belongs to the field of aerospace technology.

Description

TECHNICAL FIELD

[0001] The application relates to an aero-engine blisk blade repair forming planning method and belongs to the technical field of aerospace. BACKGROUND

[0002] In the high-pressure compressor of an aero-engine, a blisk is used to replace a tenon and slot structure blade, so that the structure is simplified, the weight is reduced, and the thrust-to-weight ratio and reliability of the engine are improved. The blisk needs to work under harsh conditions such as high temperature and high load, and is prone to damage such as edge curling, breakage and fracture. The general repair steps are as follows: after three-dimensional scanning and damage identification, the damaged part is removed to obtain a standard surface; the damage part information of the blade is reconstructed by using reverse engineering and path planning, and the damaged area is reconstructed on the standard surface by using repair processes such as laser, micro-beam plasma and electric arc according to the planned path; the machining allowance is removed through fine milling and fine polishing, and a repaired part with the same size as the original blade is obtained through post-processing.

[0003] At present, the advantage of the path planning method lies in various filling strategies, and it is mainly used for deposition forming of large structural parts. However, the high-pressure compressor blade has the characteristics of thinness, thinness and torsion, and the filling advantage of the path planning is difficult to be used for thin-walled blades. In particular, for the electric arc wire deposition process, the path planning method is imperfect and the degree of automation is low. In addition, the welding gun in the repair process is fixed in a posture, and it is difficult to realize high-quality repair forming of the twisted blade. In summary, there is still no simple and special forming planning method suitable for blade repair. SUMMARY

[0004] The application is to solve the problems of the existing blade repair path planning method, such as imperfection, low degree of automation and poor repair forming quality, and further proposes an aero-engine blisk blade repair forming planning method.

[0005] The technical solution adopted by the application to solve the above problems is as follows:

[0006] The application comprises the following steps:

[0007] Step 1, start of repair

[0008] Step 2, damage identification by using a Calibry Nest type three-dimensional scanner;

[0009] Step 3, obtaining a repair area model;

[0010] Step 4, extracting a mean camber surface of the repair area by using a finite element model preprocessing tool (HyperMesh 14.0) software;

[0011] Step 5, mean camber line path planning and deposition parameters by using a mold programming software (Mastercam2021)

[0012] Setting, welding gun posture planning, obtaining NC path;

[0013] Step 6: Import the NC path into the offline programming software (Robotmaster V7.4) to control the wire feeding direction.

[0014] Robot repair path simulation to obtain Rapid program;

[0015] Step 7: Execute the nth layer deposition instruction of Rapid program, n≥1, using BOJKE-BL-50NZ displacement sensor.

[0016] The sensor detects the deposition height. If the deposition height meets the step amount, proceed to the next step. Otherwise, return to step 5 to perform the middle arc path planning. The deposition parameter setting, welding gun posture planning, and wire feeding direction control in step 6 remain unchanged.

[0017] Step 8: Use BOJKE-BL-50NZ displacement sensor to detect whether the deposition height reaches the correction height described in step 3.

[0018] If the height of the digital model of the repair area is the same as the height of the digital model of the repair area, a repaired part is obtained; otherwise, the n-th layer deposition instruction of the Rapid program is executed, n=n+1, until the deposition height reaches the digital model height of the repair area described in step 3, and a repaired part is obtained;

[0019] Step 9. Repair is complete.

[0020] Furthermore, the damage identification in step 2 specifically includes:

[0021] Step 2.1, obtain the STL format digital model of the damaged blade;

[0022] Step 2.2: Determine the damage removal position on the STL digital model and perform Boolean difference operation with the original digital model to obtain the repaired position.

[0023] District digital model.

[0024] Furthermore, the mid-arc surface extraction in step 4 is specifically as follows:

[0025] Step 4.1: Remove the maximum curvature of the digital model leaf edge in the repair area, leaving only the leaf basin and leaf back;

[0026] Step 4.2: Use the midsurface command in HyperMesh 14.0 to generate the mid-camber surfaces of the blade basin and blade back.

[0027] Furthermore, the step 5 specifically includes the following:

[0028] Step 5.1, remove the leaf basin and the back of the leaf, only keep the middle camber surface;

[0029] Step 5.2, the middle camber surface is planned with the middle camber line path by using Mastercam2021 software, and the middle camber line path is generated by adopting the "parallel" command of multi-axis machining;

[0030] Step 5.3, the deposition parameter setting includes step amount and extension distance, the step amount is set to 0.65 mm, and the extension distance is set to 6 mm;

[0031] Step 5.4, the welding gun posture planning is realized by the "tilt axis angle" command in the tool shaft control, so that the welding gun is tilted along the middle camber surface in the process of traveling.

[0032] Further, the step 6 specifically comprises:

[0033] Step 6.1, the NC path is converted into a robot repair path by using RobotmasterV7.4 software;

[0034] Step 6.2, the calculation method of the default tool direction definition is set to "path following" to realize the wire feeding direction control.

[0035] Further, the step 7 specifically comprises:

[0036] Step 7.1, the deposition height detected by the BOJKE-BL-50NZ type displacement sensor is compared with the step amount;

[0037] Step 7.2, if the detected deposition height is small, the step amount needs to be reduced according to the actual height difference, otherwise the corresponding height difference is increased.

[0038] The beneficial effects of the present application are:

[0039] 1. The aviation engine blisk blade repair forming planning method provided by the present application avoids the redundant path planning strategy and poor pertinence of single commercial software by obtaining the middle camber surface of the repair area model to plan the middle camber line path, and is suitable for high-quality repair forming of thin-walled blades.

[0040] 2. The aviation engine blisk blade repair forming planning method provided by the present application is simple to operate, can quickly realize automatic repair of the blade, improves the standardization degree of repair, and reduces the burden of the operator. DETAILED DESCRIPTION

[0041] Fig. 1 is a flow chart of the aviation engine blisk blade repair forming planning method of the present application.

[0042] Fig. 2 is a schematic diagram of the aviation engine blisk blade repair forming planning process of the present application.

[0043] Figure 3 is a leaflet repair actual effect diagram of the blisk blade repair forming planning method of the aviation engine of the present application. DETAILED DESCRIPTION

[0044] Referring to Figure 1 , the blisk blade repair forming planning method of the aviation engine of the present application includes the following steps:

[0045] Step 1, start of repair

[0046] Step 2, damage identification, the damage identification uses a Calibry Nest type three-dimensional scanner, and specifically includes:

[0047] Step 2.1, obtain the STL format numerical model of the damaged blade;

[0048] Step 2.2, determine the damage removal position on the STL format numerical model, and perform a Boolean difference operation with the original numerical model to obtain a repair

[0049] numerical model;

[0050] Step 3, obtain the repair area numerical model;

[0051] Step 4, perform mid-surface extraction of the repair area, the mid-surface extraction uses HyperMesh 14.0 software, and specifically includes:

[0052] Step 4.1, remove the maximum curvature of the repair area numerical model blade edge, and only retain two separate surfaces of the blade basin and the blade back;

[0053] Step 4.2, generate the mid-surface of the blade basin and the blade back using the mid-surface command "midsurface" in the HyperMesh 14.0 software.

[0054] Step 5, use mold programming software (Mastercam2021) to perform mid-surface line path planning, deposition parameter

[0055] setting, welding gun posture planning, and obtain NC path, specifically including:

[0056] Step 5.1, delete the blade basin and blade back surface, and only retain the mid-surface;

[0057] Step 5.2, use the Mastercam2021 software to perform the mid-surface line path planning on the mid-surface, and generate the mid-surface line path using the "parallel" command of multi-axis machining;

[0058] Step 5.3, the deposition parameter setting includes step size and extension distance, the step size is set to 0.65 mm, and the extension distance is set to 6 mm;

[0059] Step 5.4, the welding gun posture planning is realized by the "tilt axis angle" command in the tool axis control, so that the welding gun is tilted along the cambered surface in real time during the travel.

[0060] Step 6, the NC path is imported into the offline programming software (Robotmaster V7.4) for wire feeding direction control,

[0061] Robot repair path simulation, Rapid program is obtained, specifically including:

[0062] Step 6.1, the NC path is converted into a robot repair path by using the Robotmaster V7.4 software;

[0063] Step 6.2, the calculation method of the default tool direction definition is set to "path following" to realize the wire feeding direction control.

[0064] Step 7, the n-th layer deposition instruction of the Rapid program is executed, n≥1, the deposition height is detected by using the BOJKE-BL-50NZ displacement sensor, if the deposition height meets the step amount, the next step is performed, otherwise the step 5 is returned to perform the cambered line path planning, and the deposition parameter setting, the welding gun posture planning and the wire feeding direction control in step 6 remain unchanged; specifically including:

[0065] Step 7.1, the deposition height detected by the BOJKE-BL-50NZ displacement sensor is compared with the step amount;

[0066] Step 7.2, if the detected deposition height is small, the step amount needs to be reduced according to the actual height difference, otherwise the corresponding height difference is increased.

[0067] Step 8, whether the deposition height detected by the BOJKE-BL-50NZ displacement sensor reaches the repair area numerical model height in step 3 is detected, if yes, the repaired part is obtained; otherwise, the n-th layer deposition instruction of the Rapid program is executed, n=n+1, until the deposition height reaches the repair area numerical model height in step 3, and the repaired part is obtained;

[0068] Step 8, whether the deposition height detected by the BOJKE-BL-50NZ displacement sensor reaches the repair area numerical model height in step 3 is detected, if yes, the repaired part is obtained; otherwise, the n-th layer deposition instruction of the Rapid program is executed, n=n+1, until the deposition height reaches the repair area numerical model height in step 3, and the repaired part is obtained;

[0069] Step 8, whether the deposition height detected by the BOJKE-BL-50NZ displacement sensor reaches the repair area numerical model height in step 3 is detected, if yes, the repaired part is obtained; otherwise, the n-th layer deposition instruction of the Rapid program is executed, n=n+1, until the deposition height reaches the repair area numerical model height in step 3, and the repaired part is obtained;

[0070] Step 9, the repair is completed.

[0071] Embodiment:

[0072] Referring to Figure 2 , the forming planning process includes the following steps:

[0073] I, the cambered surface of the repair area numerical model is obtained;

[0074] II, the middle arc path planning is performed, a spherical milling cutter with a diameter of 1 mm is used, and parallel milling is adopted to mill the middle arc surface;

[0075] III, the milling cutter is erected, the milling cutter is always tangent to the middle arc surface along the milling direction, a 0.5 mm radius compensation is given to coincide the milling cutter tip with the middle arc surface, the milling cutter posture is equivalent to the welding gun posture, and the middle arc path is the repair path;

[0076] IV, deposition parameters are set, the step amount is the height increment of each layer, and is set to 0.65 mm, and the extension distance is set to 6 mm to avoid arcing and arc extinguishing in the repair area;

[0077] V, the welding gun posture is tilted in real time to follow the blade surface, and the spatial forming deviation of the twisted blade is avoided;

[0078] VI, the welding gun posture is represented by TCP, and the Y axis represents the wire feeding direction. In the XOY plane, the repair path of each layer is curved, and the wire feeding direction is always tangent to the repair path along the deposition direction.

[0079] Referring to Figure 3 , the actual forming effect of the aero-engine blisk blade repair forming planning method is shown. The shown are two blade damage repair examples, and the repaired blades exhibit good spatial twist forming characteristics. The repaired parts completely cover the original master model in the repair area, and the average positive deviation is 1.58 mm and 1.51 mm respectively, so that a good machining allowance is ensured.

[0080] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, but as long as the technical solutions of the present application are not deviated, the technical essence of the present application is within the scope of the present application, and any simple modification, equivalent replacement and improvement of the above embodiments are still within the protection scope of the present application.

Claims

1. A method for planning the repair and forming of an aero-engine blisk blade, characterized in that: The method comprises the following steps: Step 1. Repair starts; Step 2: Use a 3D scanner to identify damage; Step 3: Obtain the digital model of the repair area; Step 4: Use finite element model pre-processing tool software to extract the mid-arc surface of the repair area; Step 5: Use mold programming software to plan the arc path, set deposition parameters, and plan the welding gun posture. Get NC path; Step 6: Import the NC path into the offline programming software to control the wire feeding direction and simulate the robot repair path. Get the Rapid program; Step 7: Execute the nth layer deposition instruction of the Rapid program, where n≥1, and use the displacement sensor to detect the deposition height. If the deposition height meets the step amount, proceed to the next step, otherwise return to step 5 to perform the middle arc path planning, the deposition parameter setting, welding gun posture planning, and the wire feeding direction control in step 6 remain unchanged; Step 8: The displacement sensor detects whether the deposition height reaches the height of the repair area model described in step 3. If so, Then get the repair parts; If not, execute the nth layer deposition instruction of the Rapid program, where n=n+1, until the deposition height reaches the height of the repair area digital model described in step 3 to obtain the repaired part; Step 9. Repair is complete.

2. The method for planning the repair of an aero-engine blisk blade according to claim 1, characterized in that: Damage identification in step 2 specifically includes: Step 2.1, obtain the STL format digital model of the damaged blade; Step 2.2: Determine the damage removal position on the STL digital model and perform Boolean difference operation with the original digital model to obtain the repaired position. District digital model.

3. The method for planning the repair of an aero-engine blisk blade according to claim 1, characterized in that: The mid-arc surface extraction in step 4 is specifically as follows: Step 4.1: Remove the maximum curvature of the digital model leaf edge in the repair area, leaving only the leaf basin and leaf back; Step 4.2: Use the mid-surface command in the finite element model pre-processing tool software to generate the mid-camber surfaces of the blade basin and blade back.

4. The method for planning the repair of an aero-engine blisk blade according to claim 1, characterized in that: The step 5 specifically includes the following: Step 5.1, delete the leaf basin and the back of the leaf, leaving only the mid-arc surface; Step 5.2: Use mold programming software to plan the mid-arc path for the mid-arc surface, and use the "parallel" command of multi-axis machining to generate the mid-arc path; Step 5.3: The deposition parameter settings include step size and extension distance. The step size is set to 0.65 mm and the extension distance is set to 6 mm. Step 5.4: The welding gun posture planning is achieved through the "tilt axis angle" command in the tool axis control, so that the welding gun tilts along the mid-arc surface in real time during the movement.

5. The method for planning the repair of an aero-engine blisk blade according to claim 1, characterized in that: The step 6 specifically includes: Step 6.1, using offline programming software to convert the NC path into a robot repair path; Step 6.2: Set the calculation mode of the default tool direction definition to "path following" to implement the wire feeding direction control.

6. The method for planning the repair of an aero-engine blisk blade according to claim 1, characterized in that: The step 7 specifically includes: Step 7.1, comparing the deposition height and step amount detected by the displacement sensor; Step 7.2: If the detected deposition height is small, the step amount needs to be reduced according to the actual height difference; otherwise, the corresponding height difference needs to be increased.

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