An aerofoil profile numerical control milling program adaptive adjustment and compensation method

Abstract

The present application relates to a kind of aviation blade profile numerical control milling program adaptive adjustment and compensation method, comprising the following steps: step one, part is installed to three coordinate measuring machine according to detection requirement, and the clamping of part is completed;Step two, blade profile size detection;Step three, calculate the size deviation of part;Step four, determine whether the part is qualified;Step five, cross-sectional curve compensation direction determination;Step six, each cross-sectional curve reconstruction;Step seven, cross-sectional line profile degree determination;Step eight, tool radius compensation value determination;Step nine, update tool path;Step ten, output numerical control program, complete numerical control processing.The present application not only solves the automation compensation and processing quality control of multiple model blade part blade profile numerical control milling, but also can be applied to the numerical control processing and repair of integral blisk, structural parts and other parts.

Description

Technical Field

[0001] The present invention relates to the technical field of adaptive processing and quality control of aircraft engine blade parts, and in particular to a method for adaptive adjustment and compensation of a numerical control milling program for an aircraft blade profile. Background Art

[0002] Blades are a key component of aircraft engines, and the machining quality of blade parts directly impacts the overall performance of the engine. To meet the engine's requirements for high performance, high thrust ratio, high reliability, and longevity, blades must possess high shape and dimensional accuracy, as well as excellent surface quality. Due to the complex curved shapes of blades, the difficulty of machining, high precision requirements, and low pass rates, machining errors often occur due to inadequate machining or improper tool compensation settings, severely impacting the machining quality and manufacturing cycle of blade parts.

[0003] Taking a certain journal-type stator blade of an aircraft engine as an example, the blade body surface is a complex curved surface and is processed using a five-axis machining center. Due to the deviation between the actual blade size and the theoretical model and tool wear, process personnel are required to manually adjust the CNC program in the programming software. The debugging time is long, the accuracy is relatively low, and there are many human factors involved, resulting in certain risks in the processing process. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method for adaptively adjusting and compensating a CNC milling program for an aviation blade profile. The specific technical solution is as follows:

[0005] A method for adaptively adjusting and compensating a CNC milling program for an aviation blade profile, characterized by comprising the following steps:

[0006] Step 1: Install the parts on the coordinate measuring machine according to the inspection requirements to complete the clamping of the parts;

[0007] Step 2: Blade shape and size detection

[0008] Compile a test program on a three-coordinate measuring machine to complete high-precision testing of the dimensions of each section of the blade surface;

[0009] Step 3: Calculate part size deviation

[0010] Based on the test results, the blade body surface error analysis is carried out to calculate the deviation between the actual size of each section and the theoretical model;

[0011] Step 4: Determine whether the parts are qualified

[0012] Determine whether there is a point where the deviation of each cross-sectional dimension exceeds the lower limit deviation of the part. If there is a point where the deviation exceeds the lower limit deviation, the blade is scrapped. If not, proceed to step five.

[0013] Step 5: Determine the compensation direction of the cross-section curve

[0014] The actual state of the part after processing is judged based on the deviation values ​​of the detection points on each section to determine the compensation direction of the next program. A positive deviation value indicates undercutting, while a negative deviation value indicates overcutting. Undercutting is compensated inwards, while overcutting is compensated outwards.

[0015] Step 6: Reconstruction of each section curve

[0016] Reconstruct each section curve according to the deviation value and compensation direction of each section;

[0017] Step 7: Determination of cross-section profile

[0018] Determine whether each reconstructed cross-sectional curve meets the profile requirement, if so, proceed to step eight, if not, proceed to step three;

[0019] Step 8: Determine tool radius compensation value

[0020] Calculate the difference between the adjusted profile and the theoretical profile. The difference is the tool radius compensation value. If the difference is positive, the tool will be compensated inwards, and if the difference is negative, the tool will be compensated outwards.

[0021] Step 9: Update tool path

[0022] According to the transformed blade surface model, the numerical control program is regenerated in the computer;

[0023] Step 10: Output the NC program and complete NC machining.

[0024] The preferred embodiment of the adaptive adjustment and compensation method for a CNC milling program of an aviation blade profile is that, in step one, the blade profile size detection refers to measuring the actual size of each section of the blade profile on a three-coordinate measuring machine according to a compiled detection program.

[0025] The preferred embodiment of the adaptive adjustment and compensation method for the CNC milling program of the aviation blade profile is as follows: in step 4, the qualified part judgment refers to comparing and analyzing the actual detection data of the blade profile with the theoretical model, calculating the deviation value of each cross-sectional dimension, comparing the deviation value with the limit deviation, and judging whether the blade is scrapped; the actual detection dimension is recorded as S real , the theoretical size is recorded as S refe , size deviation is recorded as S cal =S real -S refe , the upper limit deviation is recorded as L max , the lower limit deviation is recorded as L min , when S cal <L min When the blade is judged to be scrapped.

[0026] The preferred embodiment of the adaptive adjustment and compensation method for the CNC milling program of the aviation blade profile is as follows: in step 5, the cross-sectional curve compensation direction determination means determining S cal The positive or negative value, S cal For positive inward compensation, S cal It is negative outward compensation.

[0027] The preferred embodiment of the adaptive adjustment and compensation method for the CNC milling program of the aviation blade profile is as follows: in step 7, the cross-section line profile determination refers to determining whether the actual profile of each reconstructed cross-section curve meets the profile requirement, and the actual profile is recorded as P real , the theoretical profile is recorded as P refe , when P real ≤P refe , it means the contour meets the requirements.

[0028] The method for adaptive adjustment and compensation of CNC milling program for aviation blade profile, wherein the preferred embodiment is as follows: in step eight, the tool radius compensation value is determined by calculating the difference between the adjusted profile and the theoretical profile, and the tool radius compensation value is recorded as R com , that is, R com =P real -P refe , when R com For positive internal compensation, R com It is negative outward compensation.

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] The present invention realizes rapid adjustment of the CNC milling program of the blade surface and accurate compensation of the tool radius through part model measurement, deviation calculation, model reconstruction, adaptive tool path correction, and tool radius compensation value confirmation, thereby improving the processing quality of such parts and shortening the processing cycle of the parts.

[0031] This technical solution, applied to the CNC milling of the blade profile of stator blade components, is the first application of adaptive technology to achieve adaptive machining and quality control of this type of feature. Adaptive machining of the blade profile during CNC milling of the blade component, achieved by this method, achieved profile accuracy that met technical requirements. After adaptive machining, the program adjustment time for a single blade profile was reduced from three hours to one hour, achieving a transition from manual to automatic program debugging.

[0032] The implementation of this method not only solves the problems of adaptive adjustment of blade body profile CNC milling programs and automatic compensation of tool radius for blade parts of multiple models, but can also be applied to CNC machining of various types of critical parts of aircraft engines such as integral blade disks and structural parts, and has strong versatility and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A flow chart of an adaptive adjustment and compensation method for a CNC milling program of an aviation blade profile;

[0034] Figure 2 This is a schematic diagram of the calculation results of the deviation between the actual blade parts and the theoretical model;

[0035] Figure 3 Schematic diagram of compensation direction of each section of the blade surface;

[0036] Figure 4 This is a schematic diagram of the blade profile detection results after reconstruction;

[0037] Figure 5 This is a comparison diagram before and after the adjustment of the CNC milling program for the blade surface.

[0038] Pre-Path is the original tool path, Later-Path is the tool path after adaptive adjustment, a is the tool path’s feed line, and b is the tool path’s retract line. DETAILED DESCRIPTION

[0039] The present invention adopts the technical means of geometric adaptive machining, and realizes the rapid adjustment of the CNC milling program of the blade body surface and the accurate compensation of the tool radius through part model measurement, deviation calculation, model reconstruction, adaptive tool path correction, and tool radius compensation value confirmation. It is the first time that the adaptive machining technology is applied to realize the CNC machining and quality control of such features. This patent takes the CNC milling of the blade body surface of the aircraft engine stator blade as an example, combined with the attached Figure 1-5 The present invention is further described with reference to the accompanying drawings and implementation process.

[0040] A method for adaptively adjusting and compensating a CNC milling program for an aviation blade profile comprises the following steps:

[0041] Step 1: Install the parts on the coordinate measuring machine according to the inspection requirements to complete the clamping of the parts;

[0042] Step 2: Blade shape and size detection

[0043] The inspection program was compiled on the three-dimensional coordinate measuring machine to complete the high-precision inspection of the cross-sectional dimensions of the blade surface, as shown in Table 1.

[0044] Table 1 Three-coordinate detection results of blade surface

[0045] +Tol -Tol -9.5* -12* -16* -20* -30.5* -41* -51.5* -57* -62* -68* -72* CC CONT MAX 0.06 -0.08 *0.10 *0.09 *0.09 *0.09 *0.10 *0.10 *0.08 *0.08 *0.07 0.05 *0.09 CC CONT MIN 0.06 -0.08 *009 *0.07 *0.07 *0.08 *0.08 *0.07 0.06 0.06 0.05 0.04 *0.07 CV CONT MAX 0.06 -0.08 *0.12 *0.10 *0.10 *0.10 *0.10 *0.10 *0.10 *0.08 *0.07 0.06 *0.09 CV CONT MIN 0.06 -0.08 *0.01 *0.08 *0.09 *0.08 *0.09 *0.08 *0.07 0.06 0.05 0.04 *0.07 LE CONTR MAX 0.06 -0.02 *0.12 *0.10 *0.10 *0.10 *0.10 *0.10 *0.10 *0.08 *0.07 *0.07 *0.09 LE CONTR MIN 0.06 -0.02 *0.19 *0.07 *0.07 *0.07 0.06 0.05 0.05 0.06 0.05 0.04 0.06 TE CONTR MAX 0.06 -0.02 *0.11 *0.09 *0.09 *0.09 *0.09 *0.09 *0.08 *0.07 *0.07 0.06 -0.09 TE CONTR MIN 0.06 -0.02 *0.08 0.06 0.06 0.06 0.06 0.05 0.04 0.04 0.04 0.03 *0.07 STACKX 0.05 -0.05 0.01 0.00 0.00 0.01 -0.01 -0.01 -0.00 0.00 -0.01 -0.01 -0.01 STACKY 0.05 -0.05 0.03 0.02 0.02 0.02 0.01 -0.00 -0.01 -0.01 -0.02 -0.02 -0.02 STACKZ 0.10 -0.00 0.06 0.05 0.04 0.04 0.02 0.01 0.02 0.03 0.04 0.05 0.05 TWTSTANG 0.17 -0.17 -0.09 -0.08 -0.08 -0.07 -0.03 -0.00 0.04 0.05 0.10 0.16 *0.19 CHORD WID 0.20 -0.20 0.18 0.16 0.15 0.15 0.14 0.13 0.11 0.13 0.12 0.09 0.14 MAX THICK 0.12 -0.16 *0.20 *0.17 *0.17 *0.17 *0.17 *0.15 *0.13 *0.13 0.11 0.09 *0.14 aq 0.10 -0.10 -0.08 -0.07 -0.07 -0.07 -0.06 -0.05 -0.05 -0.06 -0.05 -0.04 -0.07 %out 0.1 -0.0 *100.0 *97.6 *99.6 *95.1 *95.6 *76.6 *68.2 *51.1 *15.8 *0.7 *97.2

[0046] Step 3: Calculate part size deviation

[0047] Compare the three-coordinate detection data of the blade surface with the theoretical size, and calculate the deviation value of each section of the blade surface, such as Figure 2 As shown in the figure, it can be seen from the calculation results that each section has an out-of-tolerance.

[0048] Step 4: Determine whether the part is qualified. From the comparison results of the three-coordinate inspection data and the theoretical dimensions, it can be seen that there is no dimension that exceeds the limit of each inspection index of the part. The part is judged to be qualified and can continue processing;

[0049] Step 5: Determine the compensation direction

[0050] The differences between the three-dimensional detection data of each section and the theoretical size are all positive, indicating that the part is undercut and the program needs to compensate inward;

[0051] Step 6: Reconstruction of each section curve

[0052] Reconstruct each section curve according to the deviation value and compensation direction of each section;

[0053] Step 7: Determination of cross-section profile

[0054] After testing, the contour of the reconstructed blade surface curve is 0.026, which meets the theoretical contour requirement of 0.03mm. The reconstructed blade model can be directly used for subsequent processing.

[0055] Step 8: Determine tool radius compensation value

[0056] After executing step 7, the tool radius compensation value can be calculated as R com =P real -P refe =0.026-0.03=-0.004mm, outward compensation;

[0057] Step 9: Update tool path

[0058] According to the transformed blade surface model, the numerical control program is regenerated in the computer.

[0059] Step 10: Output the NC program and complete NC machining.

Claims

1. A method for adaptive adjustment and compensation of a CNC milling program for an aviation blade profile, characterized by: The steps include: Step 1: Install the parts on the coordinate measuring machine according to the inspection requirements to complete the clamping of the parts; Step 2: Blade shape and size detection Compile a test program on a three-coordinate measuring machine to complete high-precision testing of the dimensions of each section of the blade surface; Step 3: Calculate part size deviation Based on the test results, the blade body surface error analysis is carried out to calculate the deviation between the actual size of each section and the theoretical model; Step 4: Determine whether the parts are qualified Determine whether there is a point where the deviation of each cross-sectional dimension exceeds the lower limit deviation of the part. If there is a point where the deviation exceeds the lower limit deviation, the blade is scrapped. If not, proceed to step five. Step 5: Determine the compensation direction of the cross-section curve The actual state of the part after processing is judged based on the deviation values ​​of the detection points on each section to determine the compensation direction of the next program. A positive deviation value indicates undercutting, while a negative deviation value indicates overcutting. Undercutting is compensated inwards, while overcutting is compensated outwards. Step 6: Reconstruction of each section curve Reconstruct each section curve according to the deviation value and compensation direction of each section; Step 7: Determination of cross-section profile Determine whether each reconstructed cross-sectional curve meets the profile requirement, if so, proceed to step eight, if not, proceed to step three; Step 8: Determine tool radius compensation value Calculate the difference between the adjusted profile and the theoretical profile. The difference is the tool radius compensation value. If the difference is positive, the tool will be compensated inwards, and if the difference is negative, the tool will be compensated outwards. Step 9: Update tool path According to the transformed blade surface model, the numerical control program is regenerated in the computer; Step 10: Output the NC program and complete NC machining.

2. The method for adaptively adjusting and compensating an aviation blade profile CNC milling program according to claim 1, characterized in that: In step 1, the blade surface size detection refers to measuring the actual size of each section of the blade surface on a three-dimensional coordinate measuring machine according to the compiled detection program.

3. The method for adaptively adjusting and compensating an aviation blade profile CNC milling program according to claim 1, characterized in that: In step 4, part qualification determination refers to comparing and analyzing the actual inspection data of the blade surface with the theoretical model, calculating the deviation value of each cross-sectional dimension, comparing the deviation value with the limit deviation, and determining whether the blade is scrapped; The actual detection size is recorded as S real , the theoretical size is recorded as S refe , size deviation is recorded as S cal =S real -S refe , the upper limit deviation is recorded as L max , the lower limit deviation is recorded as L min , when S cal <L min When the blade is judged to be scrapped.

4. The method for adaptively adjusting and compensating a CNC milling program for an aircraft blade profile according to claim 1, characterized in that: In step 5, the cross-section curve compensation direction is determined by determining S cal The positive or negative value, S cal For positive inward compensation, S cal It is negative outward compensation.

5. The method for adaptively adjusting and compensating a CNC milling program for an aircraft blade profile according to claim 1, characterized in that: In step 7, the cross-section profile determination refers to determining whether the actual profile of each reconstructed cross-section curve meets the profile requirement. The actual profile is recorded as P real , the theoretical profile is recorded as P refe , when P real ≤P refe , it means the contour meets the requirements.

6. The method for adaptively adjusting and compensating a CNC milling program for an aircraft blade profile according to claim 1, characterized in that: In step eight, the tool radius compensation value is determined by calculating the difference between the adjusted profile and the theoretical profile. The tool radius compensation value is recorded as R com , that is, R com =P real -P refe , when R com For positive internal compensation, R com It is negative outward compensation.

Images