In-situ vortex thickness measuring method for wall thickness of aero-engine turbine bearing fairing

Abstract

The invention discloses an aero-engine turbine bearing fairing wall thickness in-situ vortex thickness measuring method. The method comprises the steps that a comparison sample piece is machined and manufactured; marking the ground and polished air inlet front edge, sequentially carrying out CT thickness measurement on all marks, recording the marks as d2, marking the 1 / 2 position of the wall thickness of the plate, and recording the thickness d2 value of the rear half part, close to the rear end, of the comparison sample piece as the original plate thickness H; the frequency f of the plate thickness H is calculated, parameters of the eddy current flaw detector are adjusted, and the flaw detection frequency is smaller than the frequency f; determining an impedance diagram; the parameters of the eddy current flaw detector are adjusted again, the amplitude value of the gate alarm frame is located at the 1 / 2 position of the wall thickness of the plate, the parameters are stored, and file names are marked; making a corresponding table, and enabling the thickness d2 value to correspond to the amplitude point position of the impedance diagram; measuring the thickness of the air inlet edge of the part, opening the file in the step 5, adjusting parameters of the eddy current flaw detector, and measuring the thickness of the air inlet edge of the part. The method is fast and accurate, fully develops the functions of the eddy current flaw detector, and solves the problem that the conventional wall thickness cannot be measured by ultrasonic wave.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to an in-situ eddy current thickness measurement method for the wall thickness of a turbine support fairing of an aircraft engine. Background Art

[0002] At present, during the processing of aircraft engine turbine support fairings, it is necessary to bend the plate into the shape of the part, then grind off the uneven parts and polish it to make the air intake front of the turbine support fairing a smooth arc. There is no need to measure the wall thickness, and it can be directly welded and installed on the turbine support housing. Since the turbine support fairing has squeezed and over-polished conditions at the air intake front during the bending process, cracks are prone to occur during use, leading to engine failure. Therefore, it is necessary to measure the finished turbine support parts to determine whether the wall thickness at the air intake front of the turbine support fairing meets the requirements. Since the inner cavity is in a closed state, the traditional caliper measurement method cannot measure it. It is also difficult to measure the conditions where the internal bottom surface is not flat, such as squeezed conditions, by using the ultrasonic thickness measurement method.

[0003] The Chinese invention patent with the publication number CN102620625B discloses a tool and method for quickly detecting the axial dimension of the opening edge of an aircraft fairing, and uses a lower detection step shaft to detect the axial dimension of the opening edge of the aircraft fairing 2 after trimming: the lower positioning shaft 1d of the lower detection step shaft is pressed against the end face of the trimming tool 3, at this time, a gap δ3 appears between the lower detection shaft 1e of the lower detection step shaft and the end face of the aircraft fairing 2, and the lower positioning shaft 1d is placed around the end face of the trimming tool 3, and the gap δ3 is measured with a feeler gauge. If 0.3mm<δ3<0.5mm, the axial dimension of the opening edge of the aircraft fairing 2 after trimming is qualified; if δ3≤0.3mm or 0.5mm≤δ3, the axial dimension of the opening edge of the aircraft fairing 2 after trimming is unqualified. This scheme uses auxiliary tools, and detection is troublesome.

[0004] Therefore, a wall thickness measurement method that can be measured only from the outside and is not affected by the bottom surface shape is needed to quickly determine whether the wall thickness of the turbine support fairing air intake front meets the requirements. Summary of the invention

[0005] In order to solve the above problems, the present invention aims to provide an in-situ eddy current thickness measurement method for the wall thickness of a turbine support fairing of an aircraft engine.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: an in-situ eddy current thickness measurement method for the wall thickness of a turbine support fairing of an aircraft engine, comprising the following steps:

[0007] Step 1: Process and manufacture a comparison sample, on which a concave air inlet edge is provided, and the maximum depth of the concave portion is greater than 1 / 2 of the wall thickness of the raw material plate;

[0008] Step 2: Grind and polish the front half of the comparison sample at the front end according to the processing technology, draw lines on the polished intake front edge, and perform CT thickness measurement on each mark in turn and record it as d2, mark the 1 / 2 position of the plate wall thickness and record the thickness d2 of the rear half of the comparison sample at the rear end as the original plate thickness H;

[0009] Step 3: Calculate the frequency f of the plate thickness H and adjust the parameters of the eddy current flaw detector so that the flaw detection frequency is less than the frequency f;

[0010] Step 4: Determine the impedance graph, the "A" position is the zero point, the "A" position is a positive number, and the "A" position is a negative number. The "A" position is determined as follows: couple the eddy current probe to any position near the rear end of the comparison sample, press the "Balance" button of the eddy current flaw detector, and make the amplitude point of the impedance graph of the eddy current flaw detector be located at the zero point "A" of the impedance graph;

[0011] Step 5: Adjust the parameters of the eddy current flaw detector again so that the amplitude value of the gate alarm box is located at 1 / 2 of the plate wall thickness, save the parameters and mark the file name; then make a corresponding table to correspond the thickness d2 value to the impedance diagram amplitude point position;

[0012] Step 6: Measure the thickness of the air intake edge of the part. Open the file in step 5 and adjust the parameters of the eddy current flaw detector to measure the thickness of the air intake edge of the part.

[0013] Preferably, the marking method used for d2 includes Arabic numerals and English letters.

[0014] The in-situ eddy current thickness measurement method for the wall thickness of an aircraft engine turbine support fairing according to claim 1 is characterized in that the material of the comparison sample 2 is a high-temperature alloy.

[0015] Preferably, in step 2, the air intake front of the comparison sample is polished to meet the requirements of the design drawing; the rear half of the comparison sample near the rear end is not polished and remains in the original state of the raw material plate.

[0016] Preferably, the frequency f of the plate thickness H in step 3 is obtained as follows: first, the conductivity of the plate used for the comparison sample is measured with a conductivity meter, or the conductivity is found out from the material manual of the plate used, and the frequency f of the plate thickness H is calculated according to the eddy current standard penetration depth formula.

[0017] Preferably, in step 4, after determining the position of the zero point "A", the eddy current probes are coupled to the front end position of the comparison sample 2, and the gain value of the eddy current flaw detector is adjusted so that the maximum amplitude point of the impedance diagram of the eddy current flaw detector is full screen and does not exceed the display screen, and the phase value is adjusted to rotate the amplitude point display to a vertical direction, that is, the amplitude point is located in the vertical axis direction of the impedance diagram, and the positions are recorded respectively, the "A" position is the zero point, the "A" position is a positive number, and the "A" position is a negative number.

[0018] Preferably, the operation of step 6 is as follows: couple the eddy current probe to any point near the rear end of the comparison sample, press the "Balance" button of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at the zero point "A" of the impedance diagram, and then couple the eddy current probe to the air inlet edge of the part, and observe the impedance diagram display. If the amplitude point is located above the "A" position, it means that the wall thickness at this position is greater than the wall thickness at the rear end of the comparison sample 2, and the amplitude point is located below the "A" position, it means that the wall thickness at this position is less than the wall thickness at the rear end of the comparison sample 2. Record it. If the amplitude point is located below the alarm box, the wall thickness at this position is unqualified.

[0019] Preferably, after the measurement is completed, the eddy current probe needs to be coupled to any position near the rear end of the comparison sample to observe whether the amplitude point of the impedance diagram of the eddy current flaw detector is located at the zero point "A" of the impedance diagram. If not, step 6 needs to be repeated.

[0020] Compared with the prior art, the present invention has the following advantages: by using the existing eddy current flaw detection equipment and eddy current probe, measurement can be made from the front edge of the turbine support fairing air intake without being affected by the bottom surface shape, so as to improve the detection efficiency and reduce the scrapping of parts by judging whether the wall thickness meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a schematic diagram of a comparative sample of the present invention;

[0023] Figure 2 It is a schematic diagram of parts of the present invention;

[0024] Figure 3 It is a schematic diagram of impedance diagram.

[0025] In the figure, 1-part; 2-comparison sample; 3-air intake edge; 4-mark; 5-towards the front end; 6-towards the rear end. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and 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 the common technical knowledge and customary means in the field are included in the scope of the present invention.

[0027] Reference Figure 1-3 , an in-situ eddy current thickness measurement method for the wall thickness of an aircraft engine turbine support fairing, the measurement method and steps are as follows:

[0028] 1. Process and manufacture comparison sample 2. For the manufacture of comparison sample 2, use parts with deeper squeeze damage at the air intake edge 3. First, visually inspect the degree of squeeze damage. The deepest part of the depression should be greater than 1 / 2 of the wall thickness of the raw material plate. Otherwise, additional extrusion is required to make the deepest part of the depression greater than 1 / 2 of the wall thickness of the raw material plate. Then, grind and polish the front half of the front end 5 according to the processing technology. The grinding makes the air intake front edge of comparison sample 2 meet the requirements of the design drawing. The back half of the rear end 6 is not ground or polished, which is the original state of the raw material plate. Then, draw lines and marks on the air intake front edge of comparison sample 2, and make marks 4 in the order of "1", "2", "3"... Then perform CT thickness measurement on comparison sample 2, and record the thickness d2 values ​​of different positions "1", "2", "3"... of mark 4. At the same time, mark the position of 1 / 2 of the plate wall thickness, and the thickness d2 values ​​of the positions "6", "7", "8"... are the original plate thickness H.

[0029] 2. Calculate the standard penetration depth of eddy current testing. First, use a conductivity meter to measure the conductivity of the plate used for comparison sample 2, or find out the conductivity of the plate material in the material manual, and calculate the frequency f of the plate thickness H according to the eddy current standard penetration depth formula.

[0030] 3. Adjust the parameters of the eddy current flaw detector so that the detection frequency is less than the frequency f of the standard penetration depth based on the plate thickness H.

[0031] 4. Couple the eddy current probe to any of the positions "6", "7", "8"... of comparison sample 2, press the "Balance" key of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at the zero point "A" of the impedance diagram, and then couple the eddy current probe to the positions "1", "2", "3", "4"... of comparison sample 2 respectively, adjust the gain value of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector full screen at most and not exceed the display screen, adjust the phase value to rotate the amplitude point display to the vertical direction, that is, the amplitude points "B", "C", "D" and so on are located in the vertical axis direction of the impedance diagram, and record the positions respectively, the "A" position is the zero point, the "A" position is a positive number, and the "A" position is a negative number.

[0032] 5. Adjust the parameters of the eddy current flaw detector again so that the amplitude value of the gate alarm box is located at 1 / 2 of the plate wall thickness, save the parameters and mark the file name.

[0033] 6. Make a correspondence table to correspond the thickness d2 value to the amplitude point position of the impedance diagram.

[0034] 7. Measure the thickness of the air inlet edge 3 of part 1. First call out the parameters, then couple the eddy current probe to any of the "6", "7", "8"... positions of the comparison sample 2, press the "Balance" key of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at the zero point "A" of the impedance diagram, then couple the eddy current probe to the air inlet edge 3 of part 1, and observe the impedance diagram display. If the amplitude point is located above the "A" position, it means that the wall thickness at this position is greater than the wall thickness at the "6", "7", "8"... positions of the comparison sample 2; if the amplitude point is located below the "A" position, it means that the wall thickness at this position is less than the wall thickness at the "6", "7", "8"... positions of the comparison sample 2, and the results should be recorded. If the amplitude point is located below the alarm box, the wall thickness at this position is unqualified.

[0035] 8. After the measurement is completed, the eddy current probe needs to be coupled to any of the "6", "7", "8"... positions of the comparison sample 2 to observe whether the amplitude point of the impedance diagram of the eddy current flaw detector is located at the zero point "A" of the impedance diagram. If not, repeat step 7.

[0036] Embodiment, an in-situ eddy current thickness measurement method for the wall thickness of a turbine support fairing of an aircraft engine, wherein the measurement method and steps are as follows:

[0037] Comparative sample 2 is processed and manufactured. The material of comparative sample 2 is high-temperature alloy. The parts with deeper squeeze damage at the air intake edge 3 are selected for the manufacturing of comparative sample 2. The degree of squeeze damage is first visually inspected. The deepest part of the depression should be greater than 1 / 2 of the wall thickness of the raw material plate. Otherwise, additional extrusion is required to make the deepest part of the depression greater than 1 / 2 of the wall thickness of the raw material plate. Then, the front half of the front end 5 is ground and polished according to the processing technology. The grinding makes the air intake front edge of comparative sample 2 meet the requirements of the design drawings. The rear half of the rear end 6 is not ground or polished, and is the original state of the raw material plate. Then, line marks are drawn on the air intake front edge of comparative sample 2, and marks 4 are made in the order of "1", "2", "3"..., and then CT thickness measurement is performed on comparative sample 2. The thickness d2 values ​​of different positions "1", "2", "3"... of mark 4 are recorded. At the same time, the position of 1 / 2 of the plate wall thickness is marked. The thickness d2 values ​​of the positions "6", "7", "8"... are 1.2mm of the original plate thickness.

[0038] 2. Calculate the standard penetration depth of eddy current flaw detection. First, use a conductivity meter to measure the conductivity of the plate used for comparison sample 2, which is 0.65MS / m. According to the eddy current standard penetration depth formula, the frequency f of the standard penetration depth with a plate thickness H of 1.2mm is calculated to be approximately 266KHz.

[0039] 3. Adjust the parameters of the eddy current flaw detector so that the flaw detection frequency is 200KHz, which is less than the frequency of 266KHz for the standard penetration depth with a plate thickness H of 1.2mm.

[0040] 4. Couple the eddy current probe to the "8" position of comparison sample 2, press the "Balance" key of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at the zero point "A" of the impedance diagram, and then couple the eddy current probe to the "1", "2", "3", "4"... positions of comparison sample 2 respectively, adjust the gain value of the eddy current flaw detector so that the amplitude point of the impedance diagram of the eddy current flaw detector is full screen and does not exceed the display screen, adjust the phase value to rotate the amplitude point display to the vertical direction, that is, the amplitude points "B", "C", "D" and so on are located in the vertical axis direction of the impedance diagram, and record the positions respectively, the "A" position is the zero point, the "A" position is a positive number, and the "A" position is a negative number.

[0041] 5. Adjust the parameters of the eddy current flaw detector again so that the amplitude value of the gate alarm box is located at 1 / 2 of the plate wall thickness, save the parameters and mark the file name as "ZLZ001".

[0042] 6. Make a correspondence table to correspond the thickness d2 value to the amplitude point position of the impedance diagram.

[0043] 7. Measure the thickness of the air inlet edge 3 of part 1. First call out the parameter "ZLZ001", then couple the eddy current probe to the "8" position of the comparison sample 2, press the "Balance" key of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at the zero point "A" of the impedance diagram, then couple the eddy current probe to the air inlet edge 3 of part 1, and observe the impedance diagram display. If the amplitude point is located above the "A" position, it means that the wall thickness at this position is greater than 1.2 mm. If the amplitude point is located below the "A" position, it means that the wall thickness at this position is less than 1.2 mm and it should be recorded. If the amplitude point is located below the alarm box, the wall thickness at this position is unqualified.

[0044] 8. After the measurement is completed, the eddy current probe needs to be coupled to the "8" position of the comparison sample 2 to observe whether the amplitude point of the impedance diagram of the eddy current flaw detector is located at the zero point "A" of the impedance diagram. If not, repeat step 7.

[0045] The above is a detailed introduction to the in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine provided by the present invention. This article uses specific examples to illustrate the structure and working principle of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An in-situ eddy current thickness measurement method for the wall thickness of an aircraft engine turbine support fairing, characterized in that: The following steps are included: Step 1: Processing and manufacturing a comparison sample (2), wherein the comparison sample (2) is provided with a concave air inlet edge (3), wherein the maximum depth of the concave portion is greater than 1 / 2 of the wall thickness of the raw material plate; Step 2: Grind and polish the front half of the comparison sample (2) near the front end (5) according to the processing technology, draw a line mark (4) on the intake front of the grinded and polished part, and perform CT thickness measurement on each mark (4) in turn and record it as d2, mark the position of 1 / 2 of the plate wall thickness and record the thickness d2 of the rear half of the comparison sample (2) near the rear end (6) as the original plate thickness H; Step 3: Calculate the frequency f of the plate thickness H and adjust the parameters of the eddy current flaw detector so that the flaw detection frequency is less than the frequency f; Step 4: Determine the impedance diagram, with position A as the zero point, the number above position A as a positive number, and the number below position A as a negative number. Position A is determined as follows: couple the eddy current probe to any position near the rear end (6) of the comparison sample (2), and press the "balance" key of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at position A, the zero point of the impedance diagram; Step 5: Adjust the parameters of the eddy current flaw detector again so that the amplitude value of the gate alarm box is located at 1 / 2 of the plate wall thickness, save the parameters and mark the file name; then make a corresponding table to correspond the thickness d2 value to the impedance diagram amplitude point position; Step 6: Measure the thickness of the air inlet edge (3) of the part (1). Open the file in step 5 and adjust the parameters of the eddy current flaw detector to measure the thickness of the air inlet edge (3) of the part (1).

2. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: The marking methods used for marking (4) include Arabic numerals and English letters.

3. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: The material of the comparison sample (2) is a high-temperature alloy.

4. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: In step 2, the air intake front of the comparison sample (2) is polished to meet the requirements of the design drawing; the rear half of the comparison sample (2) near the rear end (6) is not polished or polished, and is in the original state of the raw material plate.

5. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: The frequency f of the plate thickness H in step 3 is obtained as follows: first, the conductivity of the plate used for the comparison sample (2) is measured with a conductivity meter, or the conductivity is found in the material manual of the plate used, and the frequency f of the plate thickness H is calculated according to the eddy current standard penetration depth formula.

6. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: In the step 4, after the position of the zero point A is determined, the eddy current probes are respectively coupled to the front end (5) of the comparison sample (2), and the gain value of the eddy current flaw detector is adjusted so that the maximum amplitude point of the impedance diagram of the eddy current flaw detector is full screen and does not exceed the display screen. The phase value is adjusted so that the amplitude point display is rotated to a vertical direction, that is, the amplitude point is located in the longitudinal axis direction of the impedance diagram, and the positions are recorded respectively, with the A position being the zero point, the position above the A position being a positive number, and the position below the A position being a negative number.

7. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: The operation of step 6 is as follows: couple the eddy current probe to any position near the rear end (6) of the comparison sample (2), press the balance key of the eddy current flaw detector to make the amplitude point of the impedance diagram of the eddy current flaw detector located at the zero point A of the impedance diagram, and then couple the eddy current probe to the air inlet edge (3) of the part (1). Observe the impedance diagram display. If the amplitude point is located above the A position, it means that the wall thickness at this position is greater than the wall thickness at the rear end (6) of the comparison sample (2). If the amplitude point is located below the A position, it means that the wall thickness at this position is less than the wall thickness at the rear end (6) of the comparison sample (2). Record it. If the amplitude point is located below the alarm box, the wall thickness at this position is unqualified.

8. The in-situ eddy current thickness measurement method for the wall thickness of the turbine support fairing of an aircraft engine according to claim 1, characterized in that: After the measurement is completed, the eddy current probe needs to be coupled to any position of the comparison sample (2) near the rear end (6) to observe whether the amplitude point of the impedance diagram of the eddy current flaw detector is located at the zero point A of the impedance diagram. If not, step 6 needs to be repeated.

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