CN109625317B

CN109625317B - Detection instrument with eddy current inspection function of airplane and engine parts

Info

Publication number: CN109625317B
Application number: CN201811439303.8A
Authority: CN
Inventors: 崔峰; 刘洪江; 于瀚程; 高峰; 李宁
Original assignee: AECC Shenyang Liming Aero Engine Co Ltd
Current assignee: AECC Shenyang Liming Aero Engine Co Ltd
Priority date: 2018-11-29
Filing date: 2018-11-29
Publication date: 2022-06-03
Anticipated expiration: 2038-11-29
Also published as: CN109625317A

Abstract

The invention discloses a detecting instrument with the eddy current inspection function of airplane and engine parts, which comprises: the test bed comprises a host, an engine grated disc probe rod, an airplane hub probe rod, an airplane main frame probe rod, an engine grated disc test block, an airplane hub test block and an airplane main frame test block; when the engine grated disc eddy current is inspected, the engine grated disc probe rod is connected with the host machine, and an inspection reference is calibrated by using an engine grated disc test block; when the vortex inspection of the airplane hub is carried out, the airplane hub probe rod is connected with the host, and an airplane hub test block is used for calibrating an inspection reference; when the main frame eddy current of the airplane is inspected, the main frame feeler lever of the airplane is connected with the host, and the main frame test block of the airplane is used for calibrating an inspection reference. The invention realizes the function integration of the prior single eddy current inspection equipment for the airplane and the eddy current inspection equipment for the aircraft engine, and realizes the eddy current inspection of the designated items of the airplane and the engine by using one type of equipment.

Description

Detection instrument with eddy current inspection function of airplane and engine parts

Technical Field

The invention relates to aviation ground support equipment, in particular to a detection instrument with functions of eddy current inspection of parts of an airplane and an engine.

Background

The existing eddy current flaw detection equipment has relatively single function, and most of the existing eddy current flaw detection equipment inspects a specific detection target or a type of detection targets. The existing eddy current inspection equipment is either special equipment for performing eddy current inspection on aeroengine components or special equipment for performing eddy current inspection on airplane components, and the existing eddy current inspection equipment for the aeroengine components is not compatible with airplane and engine component inspection functions and has a single function; the detection structure requirement of the airplane-engine component cannot be met only by designing the style of the probe according to a single airplane or engine component structure; the material of the test block and the damage data template cannot meet the detection calibration requirement.

Disclosure of Invention

The invention aims to provide a detection instrument with the eddy current inspection function of parts of an airplane and an engine, which realizes the function integration of a single eddy current inspection device for the airplane and an eddy current inspection device for an aircraft engine in the prior art and achieves the purpose of realizing the eddy current inspection of specified items of the airplane and the engine by using a single type of device.

The technical scheme of the invention is as follows: an inspection instrument for eddy current inspection of aircraft and engine components, comprising: the main machine 100, the engine labyrinth plate probe rod 200, the airplane hub probe rod 300, the airplane main frame probe rod 400, the engine labyrinth plate test block 500, the airplane hub test block 600 and the airplane main frame test block 700; when the engine labyrinth plate vortex flow is detected, the engine labyrinth plate probe rod 200 is connected with the host machine 100, and the detection reference is calibrated by using the engine labyrinth plate test block 500; during the eddy current inspection of the airplane hub, the airplane hub probe rod 300 is connected with the host 100, and an inspection reference is calibrated by using the airplane hub test block 600; during the eddy current inspection of the main frame of the airplane, the main frame probe 400 of the airplane is connected with the main machine 100, and the main frame test block 700 of the airplane is used for calibrating the inspection reference.

Preferably, the engine labyrinth plate probe rod 200 comprises a probe 201, an adjusting piece 202, a probe rod I203, a push block 204, a handle 205, a lead I206 and a plug I207; one end of the probe I203 is provided with the probe 201 through the adjusting part 202, the other end of the probe is provided with a handle 205, the handle 205 is provided with a push block 204 for driving the adjusting part 202, and the other end of the handle 205 is connected with a plug I207 through a lead I206.

Preferably, the airplane hub probe 300 comprises a detection coil II 301, a probe II 302, a lead II 303 and a plug II 304; and one end of the probe rod II 302 is provided with a detection coil II 301, and the other end of the probe rod II 302 is connected with a plug II 304 through a lead II 303.

Preferably, the airplane main frame probe 400 comprises a detection coil III 401, a positioner 402, a set screw 403, a probe III 404, a lead III 405 and a plug III 406; detection coil III 401 is installed to probe III 404 one end, and the other end passes through wire III 405 connecting plug III 406, install locator 402 and set screw 403 on the probe III 404.

Preferably, the engine labyrinth plate test block 500 is arc-shaped and is provided with two holes, and crack defects are formed in the holes and at the edges of the holes.

Preferably, the aircraft hub test block 600 is a double-sided notch comparison test block, the notch depths of the upper surface are 0.1mm, 0.2 mm, 0.4 mm and 0.6mm from left to right respectively, and the depth tolerance is +/-15% of the nominal depth value, but is not more than +/-0.05 mm; the depths of the grooves on the lower surface are respectively 0.8 mm, 1.0 mm, 1.2 mm and 1.4mm from left to right, and the allowable depth error is +/-0.1 mm; the widths of the notches are all 0.13 +/-0.01 mm.

Preferably, five holes are formed in the aircraft main frame test block 700, and the hole I has no crack; respectively etching corner cracks on the hole II, the hole III and the hole IV, wherein the etching width is as follows: 0.13 +/-0.02 mm, the angular crack depth H of the hole II is 0.67mm, and the angular crack depth H of the hole III is 1.27 mm; the crack depth H of the corner of the hole IV is 3mm, the crack lengths on the hole II, the hole III and the hole IV are equal to the depth H, and the precision grade is +/-0.05 mm; the hole V is a penetrating crack which penetrates through a thick plate, the width of the cut is 0.13 +/-0.02 mm, the length of the crack is 5mm, the depth H is 10mm, and the precision grade is +/-0.05 mm.

The invention has the following beneficial effects:

the invention realizes the function integration of the prior single eddy current inspection equipment for the airplane and the eddy current inspection equipment for the aircraft engine, and realizes the eddy current inspection of the designated items of the airplane and the engine by using one type of equipment.

Drawings

FIG. 1 is a schematic diagram of eddy current testing;

FIG. 2 is an overall block diagram of the present invention;

FIG. 3 is a schematic diagram of a host panel according to the present invention;

FIG. 4 is a structural diagram of a labyrinth plate probe rod of the engine in the invention;

FIG. 5 is a view of the structure of the aircraft hub probe of the present invention;

FIG. 6 is a structural view of a main frame probe of the aircraft according to the present invention;

FIG. 7 is a structural diagram of a labyrinth plate test block of an engine according to the present invention;

FIG. 8 is a block diagram of a main frame test block of the present invention;

FIG. 9 is a block diagram of an aircraft hub test block according to the present invention;

FIG. 10 is a schematic view of a pressure equalizing hole-a flaw detection part of a nine-stage grated disk of an engine;

FIG. 11 is an inspection area (shaded) of a frame of the aircraft structure 1;

FIG. 12 is an aircraft structure 2 frame inspection area (shaded);

FIG. 13 is a front hub eddy current inspection focus inspection area;

FIG. 14 is a main hub eddy current inspection focus inspection area;

in the figure: 100. a host; 200. a labyrinth plate probe rod of the engine; 201. a probe; 202. an adjustment member; 203. a probe rod I; 204. a push block; 205. a handle; 206. a lead I; 207. a plug I; 300. an aircraft hub feeler lever; 301. detecting a coil II; 302. a probe rod II; 303. a lead II; 304. a plug II; 400. a main frame probe rod of the airplane; 401. detecting a coil III; 402. a positioner; 403. a set screw; 404. a probe rod III; 405. a wire III; 406. a plug III; 500. a labyrinth plate test block of the engine; 600. testing an airplane hub; 700. testing an airplane main frame;

Detailed Description

The invention is described in detail below with reference to the figures and examples.

Summary of the invention

The invention discloses an eddy current flaw detector, which is common aviation ground support equipment and is mainly used for nondestructive flaw detection of structural members such as wheel hubs of front/main aircraft wheels, movable rims, structural frames and the like and pressure-equalizing holes of nine-stage grated disks of engines.

Second, the working principle (as shown in figure 1)

Eddy current testing is one of many NDT (non-destructive testing) methods, which uses the basic theory of electromagnetism as the basis for conductor testing. When the surface or the near surface of the conductor has defects or some properties of the measured metal material are changed, the strength and the distribution of the eddy current are changed, and the existence of the defects in the conductor and whether the metal is changed or not are indirectly guided by detecting the change condition of the eddy current.

The principle of the eddy current flaw detector is that an exciting coil is used to generate an eddy current in a conductor member, and a detecting coil is used to measure the variation of the current, thereby obtaining information about the defect of the member. According to the shape of the detection coil, the detection coil can be divided into a through type (for wire, rod and pipe), a probe type (for local detection of the surface of a component) and an insertion type (for internal detection of a pipe hole). The probe type and the insertion type are adopted by the device.

Third, the general design (as shown in figure 2)

And the host/system software is redeveloped and designed for integrating three functions of nine-stage labyrinth plate eddy current flaw detection of the engine and flaw detection of the airplane hub and the airplane structure frame. The newly developed probe rod for detecting flaws of the airplane hub and the airplane structure frame redesigns protection with specific environmental adaptability.

After the eddy current flaw detector is integrally designed, the sample piece is provided with two packing boxes, one is a mainframe box and the other is a probe rod box, and the eddy current flaw detector is more in eddy current inspection work of an engine, more frequent in use and more in configuration quantity.

An inspection instrument for eddy current inspection of aircraft and engine components, comprising: the main machine 100, the engine labyrinth plate probe rod 200, the airplane hub probe rod 300, the airplane main frame probe rod 400, the engine labyrinth plate test block 500, the airplane hub test block 600 and the airplane main frame test block 700; when the engine labyrinth plate vortex flow is detected, the engine labyrinth plate probe rod 200 is connected with the host machine 100, and the detection reference is calibrated by using the engine labyrinth plate test block 500; during the eddy current inspection of the airplane hub, the airplane hub probe rod 300 is connected with the host 100, and an inspection reference is calibrated by using the airplane hub test block 600; during the eddy current inspection of the main frame of the airplane, the main frame probe 400 of the airplane is connected with the main machine 100, and the main frame test block 700 of the airplane is used for calibrating the inspection reference.

Design of host (as shown in figure 3)

Functional design of a host:

easy and simple to handle: menu prompt, hot key help.

Operation menu: the main menu and the sub-menu are displayed directly, and the operation interface is visual.

Show that: an EL panel (organic electroluminescence display panel) is used.

Data analysis: the instrument can play back, analyze and print the acquired signals.

Data storage: the detection parameters, graphs and files can be stored in the instrument and called at any time.

Data communication: can communicate with a computer or the like through a network port or a USB communication interface to transmit data such as instrument graphs and files.

Portable utility: small volume, light weight, low energy consumption, compact and light structure. The AC/DC integrated power supply module can continuously work for more than 8 hours under the power supply of a battery.

Balancing: the rapid analog balancing technology and the digital electronic balancing technology are adopted.

Gain adjustment: the advanced gain technology has large adjustable range and fine adjustment step length.

Display function: it has the functions of multi-trace graphic display, automatic calendar and time display, and on-line operation prompting help display.

Simple application: the detected surface does not need to be processed; the detected object does not need to be specially magnetized.

High sensitivity: the location and size of the metal defects can be determined during the inspection process.

The structure design of the host machine:

the eddy current flaw detector is an integrated portable device, which is operated by an electroluminescent display screen and a touch keyboard and is internally provided with a rechargeable battery. The user can select and configure external equipment such as a printer according to the detection requirement. The instrument adopts a full digital design, a computer is arranged in the instrument, excessive control knobs for driving a plate switch are not needed, and all functions and operations are controlled by software.

Probe rod design

1. Engine labyrinth disc probe rod

As shown in FIG. 4, the engine labyrinth plate probe rod 200 is composed of a probe 201, an adjusting piece 202, a probe rod I203, a push block 204, a handle 205, a lead I206 and a plug I207. The probe 201 is used for eddy current testing, the adjusting piece 202 is used for adjusting an entrance probe mouth and adjusting the measuring angle of the probe 201, the probe rod I203 adapts to the operation space for adjusting and forming, the push block 204 is used for adjusting and moving to drive the adjusting piece 202, the handle 205 is used for being held by an operator, the lead I206 is used for transmitting electric signals, and the plug I207 is used for being connected with the host computer 100 to transmit the electric signals. The probe rod detection end part is designed into a manual variable bending angle, and the flaw detection direction change of the probe at 90 degrees and 180 degrees is realized.

The engine labyrinth plate probe rod 200 can enter a flaw detection part in an engine installation state, the probe 201 is kept straight through the position of an engine observation opening cover, and can enter a pressure equalizing hole parallel to the axis of an engine during flaw detection.

2. Airplane hub probe rod

As shown in fig. 5, the airplane hub probe 300 is composed of a detection coil ii 301, a probe ii 302, a lead ii 303 and a plug ii 304; the detection coil II 301 is used for eddy current detection, the probe II 302 is used for being held by an operator, and the lead II 303 and the plug II 304 are used for electric signal transmission.

The aircraft hub probe 300 is a general eddy current flaw detection probe and is mainly used for detecting cracks on the surface of a hub. Aircraft wheel hub probe 300 is hand-held type, by longer pencil connecting socket, and middle probe II 302 is shorter, conveniently stretches into when the position of detecting a flaw is narrower and detects a flaw.

3. Airplane main frame probe rod

As shown in fig. 6, the main frame probe 400 of the airplane is composed of a detection coil iii 401, a locator 402, a set screw 403, a probe iii 404, a lead iii 405, and a plug iii 406; the detection coil III 401 is used for eddy current detection, the positioner 402 is used for adjusting and positioning a detection position, the probe rod III 404 is used for holding, and the lead III 405 and the plug III 406 are used for transmitting electric signals.

The aircraft main frame probe 400 primarily detects cracks in the hole. The length of the detection coil III 401 extending out of the fixed seat is adjusted by the airplane main frame probe rod 400 through the positioning screw 403, so that the depth of the detection coil III 401 extending into the detected hole is adjusted. After the main frame probe rod 400 of the airplane is used, the probe is kept to be vertically inserted into the hole to be detected, the positioning screw 403 can be rotated only after being locked by a special screwdriver, and the probe rod III 404 also needs to be kept to be vertical to the direction in the hole when rotating.

Design of test block

1. Engine labyrinth disk test block

The engine labyrinth plate test block 500 is designed according to the material and the structure of a detection part. The engine labyrinth plate test block 500 is designed to be arc-shaped and 5mm thick, and two holes are formed in the upper surface of the engine labyrinth plate test block and are respectively 5.0mm and 5.2mm in size. Crack defects were made in and at the hole edges, and the defect sizes are shown in FIG. 7. The defects are used for eddy current inspection standard comparison.

2. Airplane main frame test block

The airplane main frame test block 700 is made of the same materials as the airplane structure 1 frame and the airplane structure 2 frame. Simulating a main frame structure by the main frame test block structure of the airplane before manufacturing artificial defects; the hole I has no cracks; respectively etching corner cracks on the hole II, the hole III and the hole IV, wherein the etching width is as follows: 0.13 +/-0.02 mm, the angular crack depth H of the hole II is 0.67mm, and the angular crack depth H of the hole III is 1.27 mm; the crack depth H of the corner of the hole IV is 3mm, the crack lengths on the hole II, the hole III and the hole IV are equal to the depth H, and the precision grade is +/-0.05 mm; the hole V is a penetrating crack which penetrates through a thick plate, the width of the cut is 0.13 +/-0.02 mm, the length of the crack is 5mm, the depth H is 10mm, and the precision grade is +/-0.05 mm. Marking the length of the cut on the side surface by using electrochemical etching, wherein the marked mark is on the same side as the crack; and the small hole with the diameter of 2.5mm beside the small hole with the diameter of 6.5mm is riveted on the thicker test block before the two layers of test blocks are riveted. And riveting the two layers of test blocks through 6 rivets, wherein the aperture of each rivet is 4 mm.

3. Airplane hub test block

The airplane hub test block 600 is a double-faced notch reference test block for evaluating the defect depth by referring to GJB 2908-97 vortex inspection method standard, and is manufactured by adopting double-faced notches. The material of the reference test block for hub eddy current inspection is the same as that of the tested part.

The depth of the upper surface groove is 0.1mm, 0.2 mm, 0.4 mm and 0.6mm from left to right respectively, and the allowable depth error is +/-15% of the nominal depth value, but not more than +/-0.05 mm; the depths of the grooves on the lower surface are respectively 0.8 mm, 1.0 mm, 1.2 mm and 1.4mm from left to right, and the allowable depth error is +/-0.1 mm; the widths of the notches are all 0.13 +/-0.01 mm. Before manufacturing artificial defects, carrying out fluorescence penetration detection according to GJB2367A-2005, wherein the artificial defects on the reference block can be longitudinally or transversely grooved, and the section type of the grooves is V-shaped. And the grooves on the reference block are machined, electrosparking or chemically corroded. The test piece is not allowed to deform during processing. No other surface openings are allowed to show.

Seventh, eddy current testing method

1. Nine-stage grated disk of engine

The flexible bore sonde is prepared to be in a standby state. And inserting a flexible probe of the hole detector into a hole in the upper part of the inner duct support plate of the engine. And adjusting the flexible probe of the hole detector to the far end position of the nine-stage grate disc pressure-equalizing hole, adjusting the direction of the probe, ensuring that the hole detector can see the nine-stage grate disc pressure-equalizing hole and the probe rod sensor, and locking the probe of the hole detector.

And adjusting a probe rod handle push block of the eddy current flaw detector to enable the sensor to be in a stretched state, and inserting the probe rod sensor into a hole in the lower portion of the support plate. And after the probe rod sensor is inserted, the probe rod sensor of the eddy current flaw detector is restored to be in a free vertical state. The high-pressure rotor of the engine is slowly rotated by a special rocking tool for a certain angle, so that one pressure equalizing hole of the nine-stage grate disc is positioned right opposite to the probe rod sensor.

And observing the checked pressure equalizing hole and a probe rod sensor through a hole detector, wherein the sensor is vertically inserted into the first pressure equalizing hole of the nine-stage labyrinth disc of the high-pressure compressor.

After the first pressure equalizing hole is checked, the sensor is vertically pulled out and kept at a position to be inserted, the high-pressure rotor is rotated, and the hole detector is used for observing that the next pressure equalizing hole of the nine-stage grate disc is positioned at the insertion position of the probe rod sensor.

And repeating the previous flaw detection work of the pressure equalizing hole to perform flaw detection.

2. Airplane structure frame

Fatigue cracking of the inner wall of 16 pallet nut holes 6.5H9 (inside the ellipse in the figure) in the frame area of the aircraft structure 1 (see figure 11).

Fatigue cracking of the inner wall of 9 pallet nut holes 6.5H9 (inside the ellipse in the figure) in the frame area of the aircraft structure 2 (see figure 12).

And (3) detaching 16 self-locking nuts in the frame area of the structure 1 and 9 self-locking screws in the frame area of the structure 2 from the airplane. And removing the corresponding skin of the airplane. The probe rod probe is vertically inserted into the hole, the probe rod is rotated for one circle to two circles, and the probe rod probe is also kept vertical to the direction in the hole during rotation. And (4) inspecting nut holes of all the aircraft structure frame support plates according to sequential flaw detection.

And (4) calibrating the sensor once by using the test block every time 5-10 holes are inspected, continuously inspecting after the calibration is abnormal, and repeatedly inspecting the inspected nut holes of the support plate after the calibration is abnormal.

And after the inspection is finished, recovering the aircraft structure frame skin and recovering the corresponding supporting plate nut self-locking screw.

3. Airplane hub

And (5) detaching the hub. The probe is lightly placed vertically at the examination site. And (3) checking for one week in a W scanning mode, wherein the scanning distance is less than 2mm, and the scanning speed is about 25 mm/s. And (4) scanning all the inspection parts of the inner half hub in sequence, and recalibrating the equipment by using the test block when the outer half hub is replaced and inspected.

If a signal forming a certain included angle with the shaking signal appears and enters the alarm frame, a crack defect may exist. When a suspected crack is found, the signal is "rebalanced" and inspected repeatedly as being in good proximity to verify that the signal is of good reproducibility.

During scanning, the probe is kept vertical to the inspection surface, and the signal track is observed. If the signal enters the alarm frame along the shaking signal track, the crack is not indicated; the real crack signal enters the alarm frame from the balance point and the shaking signal at a certain included angle.

The parameters of the nine-stage grated disk flaw detection module of the flaw detection engine are normal through field debugging, the parameters of the online debugging of the host, the probe and the test block are normal, and the defects can be displayed and alarmed. The state test of the ignition electric nozzle is not disassembled on the airplane, the nine-stage labyrinth plate eddy current flaw detection of the left engine and the right engine can be completed, and the use is good.

The invention has the advantages of ground debugging, normal parameters of the hub eddy current inspection module, normal online debugging parameters of the main machine, the probe and the test block, capability of displaying and alarming for defects, capability of carrying out on-board test on the flaw detection of structural members such as main wheels of an airplane, front/main wheel hubs, movable rims and the like, and good use.

The invention has the advantages of ground debugging, normal parameters of the main frame eddy current inspection module, normal online debugging parameters of the main machine, the probe and the test block, capability of displaying and alarming for defects, capability of carrying out on-board test on the inner hole wall of 16 supporting plate nut holes 6.5H9 in 1 frame of the airplane structure and excellent use for carrying out inspection on the inner hole wall of 9 supporting plate nut holes 6.5H9 in 2 frames of the airplane structure.

According to the invention, through the optimized design, the use functions of different equipment are integrated, the technical indexes of the eddy current flaw detection of the engine and the airplane of a specified project are completed, the inspection work of the specified project by using two sets of equipment is functionally replaced, the equipment purchase cost is saved, the utilization rate of aviation ground guarantee equipment is improved, the maintenance cost of the equipment is reduced, and the development requirements of integration, generalization and miniaturization of the aviation ground guarantee equipment are met.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. An inspection instrument having both aircraft and engine component eddy current inspection functionality, comprising: the system comprises a main machine (100), an engine labyrinth disc probe rod (200), an airplane hub probe rod (300), an airplane main frame probe rod (400), an engine labyrinth disc test block (500), an airplane hub test block (600) and an airplane main frame test block (700); when the engine grated disc eddy current is inspected, the engine grated disc probe rod (200) is connected with the host (100), and an inspection reference is calibrated by using an engine grated disc test block (500); when the vortex inspection of the airplane hub is carried out, the airplane hub probe rod (300) is connected with the host (100), and an airplane hub test block (600) is used for calibrating an inspection reference; when the main frame eddy current inspection of the airplane is carried out, the main frame probe rod (400) of the airplane is connected with the main machine (100), and the main frame test block (700) of the airplane is used for calibrating an inspection reference; the engine labyrinth plate probe rod (200) comprises a probe (201), an adjusting piece (202), a probe rod I (203), a push block (204), a handle (205), a lead I (206) and a plug I (207); one end of the probe I (203) is provided with a probe (201) through an adjusting piece (202), the other end of the probe I is provided with a handle (205), a push block (204) for driving the adjusting piece (202) is arranged on the handle (205), and the other end of the handle (205) is connected with a plug I (207) through a lead I (206); the airplane hub probe rod (300) comprises a detection coil II (301), a probe rod II (302), a lead II (303) and a plug II (304); one end of the probe rod II (302) is provided with a detection coil II (301), and the other end of the probe rod II (302) is connected with a plug II (304) through a lead II (303); the airplane main frame probe rod (400) comprises a detection coil III (401), a positioner (402), a positioning screw (403), a probe rod III (404), a lead III (405) and a plug III (406); probe rod III (404) one end installation detection coil III (401), the other end passes through wire III (405) attach plug III (406), installation locator (402) and set screw (403) are gone up in probe rod III (404).

2. The testing instrument for eddy current inspection of both aircraft and engine parts as claimed in claim 1, wherein said engine labyrinth plate block (500) is arc-shaped and has two holes therein, and crack defects are provided in and at the edges of the holes.

3. The testing instrument for the eddy current inspection of the aircraft and the engine part as claimed in claim 1, wherein the aircraft hub test block (600) is a double-faced grooved reference test block, the depths of the grooves on the upper surface are respectively 0.1, 0.2, 0.4 and 0.6mm from left to right, and the allowable depth error is +/-15% of the nominal depth value but not more than +/-0.05 mm; the depths of the grooves on the lower surface are 0.8 mm, 1.0 mm, 1.2 mm and 1.4mm from left to right respectively, and the allowable error of the depth is +/-0.1 mm; the widths of the notches are all 0.13 +/-0.01 mm.

4. The inspection instrument for the eddy current inspection of the components of the aircraft and the engine together according to claim 1, wherein five holes are formed on the test block (700) of the main frame of the aircraft, and the hole I has no crack; respectively etching corner cracks on the hole II, the hole III and the hole IV, wherein the etching width is as follows: 0.13 +/-0.02 mm, the angular crack depth H of the hole II is 0.67mm, and the angular crack depth H of the hole III is 1.27 mm; the crack depth H of the corner of the hole IV is 3mm, the crack lengths on the hole II, the hole III and the hole IV are equal to the depth H, and the precision grade is +/-0.05 mm; the hole V is a penetrating crack which penetrates through a thick plate, the width of the cut is 0.13 +/-0.02 mm, the length of the crack is 5mm, the depth H is 10mm, and the precision grade is +/-0.05 mm.