Composite guide vane surface inspection equipment

Abstract

The present application relates to the field of optical technology, especially to a composite guide vane surface flaw detection device, comprising a blue light scanning detection system and a support for loading guide vanes to be detected, the guide vanes to be detected being placed vertically; further comprising a laser interferometer; the laser interferometer comprises a laser, a beam splitter and a grating, the beam splitter divides the incident light beam into a measurement light beam and a reference light beam; a transparent glass cylinder with an internal pressure-adjustable gas is arranged on the light path of the measurement light beam; the included angle between the measurement light beam and the reference light beam in the vertical direction is greater than 30° and less than 90°; further comprising an optical collimation system, the optical collimation system comprises two light-shielding channels parallel to the pointing directions of the measurement light beam and the reference light beam. The blue light scanning and the laser interferometer are combined to realize efficient and accurate high-precision defect detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to a composite guide vane surface inspection equipment. BACKGROUND

[0002] The guide vane of an aero-engine is a key aerodynamic component in turbomachinery, usually located in the compressor or turbine section, and its core function is to efficiently transfer energy by adjusting the direction of airflow. These blades are usually made of high-temperature alloys or ceramic matrix composites to withstand extreme high temperature, high pressure and high speed working environment.

[0003] The smoothness of the guide vane surface is directly related to the flow state of air or gas. Any small surface protrusions (including burrs, welds) and depressions (including scratches, pits) will disrupt the smooth and orderly flow of air or gas, become stress concentration points and cause guide vane fatigue fracture, and further lead to performance degradation or failure of the aero-engine. Therefore, after the guide vane is manufactured, its surface must be non-destructively tested to ensure that it meets the reliability requirements under extreme working conditions.

[0004] A blue light scanner is usually used to project blue light on the guide vane for non-destructive testing to quickly obtain full-size three-dimensional topographic data of the guide vane, and compare it with the design data to detect whether the surface geometric parameters of the guide vane are out of tolerance. However, the detection accuracy of the blue light scanner is limited and it is difficult to meet the higher precision detection requirements of the guide vane surface. SUMMARY

[0005] The purpose of the present application is to provide a composite guide vane surface inspection equipment to solve at least one of the above technical problems.

[0006] The technical problem solved by the present application can be realized by the following technical scheme:

[0007] The composite guide vane surface inspection equipment comprises a blue light scanning detection system and a support for loading a guide vane to be detected, and the guide vane to be detected is vertically placed.

[0008] It also comprises a laser interferometer.

[0009] The laser interferometer comprises a laser, a beam splitter and a grating, and the beam splitter divides the incident light beam into a measurement light beam and a reference light beam.

[0010] A transparent glass cylinder with adjustable internal pressure is arranged on the optical path of the measurement light beam.

[0011] The included angle between the measurement light beam and the reference light beam in the vertical direction is greater than 30° and less than 90°.

[0012] It also comprises an optical collimation system, which comprises two light-shielding channels parallel to the pointing direction of the measurement light beam and the reference light beam, respectively.

[0013] The inner wall of the light shielding channel is a straight circular tube with a black frosted structure;

[0014] The rear of each of the two light shielding channels is provided with an optical assembly system for adjusting the angle of light;

[0015] The two optical assembly systems adjust the return light beams transmitted by the two light shielding channels and then interfere with each other;

[0016] The to-be-detected guide vane is located on the light paths of the measurement light beam and the reference light beam;

[0017] The reference light beam and the measurement light beam are reflected by the surface of the to-be-detected guide vane to form two reflected light beams, the reflected light beams filtered by the light shielding channel enter the optical assembly system and then are projected onto a grating to form an interference image;

[0018] The reference light beam and the measurement light beam are aligned with the intact area of the surface of the to-be-detected guide vane to obtain a standard interference image;

[0019] The laser interferometer is horizontally rotated and vertically displaced to move the reference light beam and the measurement light beam synchronously, thereby scanning the to-be-detected guide vane, and when a change exceeding a set threshold is detected in the interference image, a defect point is marked.

[0020] The above design quickly locates a suspected defect area by a blue light scanning detection system, and then uses a laser interferometer to recheck the suspected defect area with high precision, thereby improving the detection precision and shortening the detection time.

[0021] A traditional interferometer is a high-precision measuring instrument based on the principle of laser interference, which is internally provided with a laser and a beam splitter.

[0022] During the scanning process of the laser interferometer, the relative displacement and the relative angle change between the laser interferometer and the to-be-detected guide vane are inevitable.

[0023] The traditional laser interferometer uses a fixed reference mirror, and during the scanning process between the laser interferometer and the to-be-detected guide vane, the relative displacement or the relative angle change is inevitable at least on the micron level, which causes irregular jumps in interference imaging and thus cannot scan the damage position.

[0024] In the present patent application, the reference mirror is deleted, and the surface of the to-be-detected guide vane receives the measurement light beam and the reference light beam which move synchronously.

[0025] In the scanning process between the laser interferometer and the guide vane to be detected, although the relative displacement or relative angle change is still generated, the optical path difference between the measurement beam and the reference beam is synchronously changed, and is almost not affected by the slight change in the position between the laser interferometer and the guide vane to be detected.

[0026] Furthermore, in the scanning process, the problem of irregular jump of interference imaging does not occur, so that the position of the tiny damage can be accurately scanned, and theoretically, the scanning accuracy can be in the order of microns or even nanometers.

[0027] A transparent glass cylinder filled with an internal pressure-adjustable gas is arranged on the optical path of the measurement beam, and the transparent glass cylinder is filled with sulfur hexafluoride gas. By adjusting the pressure of the sulfur hexafluoride gas in the transparent glass cylinder, the refractive index is changed, and then the measurement beam and the reference beam generate standard interference to form a standard interference image that is easy to distinguish.

[0028] The scheme in the patent application removes the reference mirror, and adjusts the interference image by moving the laser interferometer and the relative position of the guide vane to be detected. This is extremely complex, time-consuming, and difficult to achieve, and it is almost impossible to achieve by moving the macro mechanical scale to synchronously adjust the double beams in micron accuracy to present an ideal interference image.

[0029] In the patent application, the optical path of the single reference beam is adjusted extremely accurately by adjusting the gas pressure. Based on the relationship between the refractive index and the pressure, the pressure control accuracy of the gas pump in the prior art, and the relatively large size of the transparent glass cylinder used in the patent, the optical path difference accuracy can be adjusted to the nanometer level.

[0030] First, the adjustment process becomes extremely simple and fast, and ordinary workers can easily operate and implement it.

[0031] Second, the adjustment level of the optical path difference is accurately adjusted to the nanometer level, which is beyond the reach of macro mechanical adjustment, and provides a higher level of measurement basis for accurate measurement.

[0032] Moreover, the relative position of the laser interferometer and the guide vane to be detected is not moved during the adjustment process. It should be noted that under the measurement accuracy of microns, it is extremely difficult to adjust the interference image by moving the macro mechanical scale.

[0033] The laser interferometer in the above design is further provided with an optical collimation system and an optical component system.

[0034] Because the orientations of the two light-blocking channels are fixed, the optical component system for adjusting the angle of the light is easy for those skilled in the art to implement, and therefore will not be described in detail here.

[0035] Two reflected light beams enter the light-shielding channel. Light beams pointing nearly parallel to the channel pass through, while beams with excessively large angles are absorbed by the black frosted structure. By using a straight, cylindrical light-shielding channel with a black frosted inner wall, stray light is absorbed, multiple reflections are suppressed, and only light beams propagating along the channel's axis are allowed to pass through. Light beams with excessively large angles are blocked by the tube wall, and the black frosted straight cylindrical inner wall absorbs deviated light beams hitting the tube wall, reducing the impact of stray light on interference imaging.

[0036] Preferably, two reflected light rays enter the light-shielding channel. The light rays that are nearly parallel to the direction of the light-shielding channel pass through the light-shielding channel, while the light rays with a large angle difference are absorbed by the black frosted structure.

[0037] Preferably, the following process is used during application:

[0038] S1: Place the guide vane to be tested on the support;

[0039] S2: The blue light scanning detection system includes a blue light scanner, which projects blue light stripes onto the surface of the guide vane to be inspected and acquires three-dimensional morphological data of the surface of the guide vane to be inspected.

[0040] S3: Compare the obtained 3D topography data with the design data, and mark the deviation areas as suspected problem areas;

[0041] S4: Move the laser interferometer to the side of the suspected problem area, so that the reference beam and the measurement beam are focused on the smooth and intact surface next to the suspected problem area;

[0042] S5: Adjust the air pressure in the transparent glass tube to change the refractive index, thereby correcting the optical path difference and obtaining a standard interference image;

[0043] S6: The laser interferometer rotates horizontally to move the reference beam and the measurement beam synchronously, scanning the guide vane to be tested and obtaining multiple sets of measurement interference images;

[0044] S7: Compare the measured interferometric image with the standard interferometric image. When a change in the interferometric image exceeding a set threshold is detected, mark it as a defect point.

[0045] Preferably, the laser interferometer has a measurement beam exit port for transmitting the measurement beam and a reference beam exit port for transmitting the reference beam; the measurement beam exit port and the reference beam exit port also serve as light inlets for reflected light, respectively.

[0046] Preferably, the length of the light-shielding channel is 5cm to 10cm and the diameter is 0.5cm to 1cm. The length and diameter of the light-shielding channel can effectively block stray light and improve the stability of reflected light during transmission, thereby improving measurement accuracy and reliability.

[0047] Preferably, the laser interferometer is fixed on a holder, and a hydraulic rod for controlling the vertical movement of the holder is connected to the lower surface of the holder.

[0048] Preferably, the transparent glass cylinder is in a sealed structure, and the end surfaces at both ends of the transparent glass cylinder are flat.

[0049] The end surfaces at both ends of the transparent glass cylinder are perpendicular to the direction of the light path of the measuring light beam.

[0050] Preferably, the device further comprises a gas pump and a sulfur hexafluoride gas source, and a gas supply port is arranged on the transparent glass cylinder and communicates between the inside and outside of the transparent glass cylinder; the gas supply port is connected to the gas pump, the gas pump is connected to the sulfur hexafluoride gas source, and the gas pump fills or discharges sulfur hexafluoride gas into the transparent glass cylinder, so as to adjust the gas pressure in the transparent glass cylinder.

[0051] Preferably, the inner cavity of the transparent glass cylinder has a cross-sectional area greater than 5 square centimeters and less than 10 square centimeters.

[0052] In summary, the present application has the following advantages:

[0053] 1. The suspected defect area is quickly positioned by the blue light scanning detection system, and then the suspected defect area is re-inspected by the laser interferometer, so as to improve the detection accuracy and shorten the detection time, and the fixed reference mirror in the traditional laser interferometer is deleted, the surface of the guide vane to be detected receives the measuring light beam and the reference light beam which synchronously move, the problem of irregular jump of interference imaging in the scanning process is solved, the detection accuracy reaches micrometer level or even nanometer level, and extremely small damage can be accurately identified.

[0054] 2. The transparent glass cylinder with an internal pressure-adjustable gas is arranged on the light path of the measuring light beam, sulfur hexafluoride gas is pumped into or discharged from the transparent glass cylinder, the pressure of the sulfur hexafluoride gas in the transparent glass cylinder is adjusted, the refractive index is changed, the optical path of the single reference light beam is extremely accurately adjusted, the optical path difference is corrected, a standard interference image which is easy to distinguish is formed, the adjustment process is simple and fast, and ordinary workers can easily operate and realize. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 FIG. 1 is a schematic structural diagram of the overall structure of the composite guide vane surface flaw detection device of the present application;

[0056] Figure 2 FIG. 2 is a schematic structural diagram of the composite guide vane surface flaw detection device of the present application; Figure 1 FIG. 3 is an enlarged structural schematic diagram of position A in FIG. 2;

[0057] Figure 3 The structural diagram for embodying the light guide cylinder of the composite guide vane surface inspection equipment.

[0058] In the figure, 1 is a guide vane to be detected; 2 is a support; 3 is a blue light scanner; 4 is a laser interferometer; 5 is a beam splitter; 6 is a measurement beam; 7 is a reference beam; 8 is a hydraulic rod; 9 is a pan-tilt; 10 is a transparent glass cylinder; and 11 is an air pump. DETAILED DESCRIPTION

[0059] In order to make the technical means, creative features, purposes and effects of the application easy to understand, the application is further described below in combination with specific drawings.

[0060] REFERENCE Figures 1 to 3 The composite guide vane surface inspection equipment, the blue light scanning detection system, and the support 2 loaded with the guide vane 1 to be detected, the guide vane 1 to be detected is vertically placed;

[0061] The laser interferometer 4 is further included;

[0062] The laser interferometer 4 includes a laser, a beam splitter 5, and a grating, the beam splitter 5 divides the incident light beam into a measurement beam 6 and a reference beam 7;

[0063] A transparent glass cylinder 10 with an internal pressure-adjustable gas is arranged on the light path of the measurement beam 6;

[0064] The included angle between the measurement beam 6 and the reference beam 7 in the vertical direction is greater than 30° and less than 90°;

[0065] An optical collimation system is further included, the optical collimation system includes two light-shielding channels parallel to the pointing directions of the measurement beam 6 and the reference beam 7 respectively;

[0066] The inner wall of the light-shielding channel adopts a straight circular tube-shaped inner wall with a black frosted structure;

[0067] An optical assembly system for adjusting the light angle is arranged behind each of the two light-shielding channels;

[0068] The two optical assembly systems respectively adjust the returned light beams transmitted by the two light-shielding channels and then perform interference;

[0069] The guide vane 1 to be detected is located on the light paths of the measurement beam 6 and the reference beam 7;

[0070] The reference beam 7 and the measurement beam 6 form two reflected light beams after being reflected by the surface of the guide vane 1 to be detected, the reflected light beams filtered by the light-shielding channel enter the optical assembly system and are projected to the grating to form an interference image;

[0071] The reference beam 7 and the measurement beam 6 are aligned with the intact area on the surface of the guide vane 1 to be detected to obtain a standard interference image;

[0072] The laser interferometer 4 performs horizontal rotation and up-down displacement to synchronously move the reference light beam 7 and the measurement light beam 6 to scan the guide vane 1 to be detected, and marks a defect point when a change exceeding a set threshold is detected in an interference image.

[0073] In the above design, the suspected defect area is quickly positioned by the blue light scanning detection system, and then the suspected defect area is rechecked by the laser interferometer 4 to improve the detection accuracy and shorten the detection time.

[0074] During the scanning process of the laser interferometer 4, the relative displacement and the relative angle change between the laser interferometer 4 and the guide vane 1 to be detected are difficult to avoid.

[0075] The traditional interferometer is a high-precision measuring instrument based on the laser interference principle, and a fixed reference mirror is used. During the scanning process between the laser interferometer 4 and the guide vane 1 to be detected, the relative displacement or the relative angle change is unavoidable, at least on the micron level, and irregular jumps of interference imaging occur, and thus the damage position cannot be scanned.

[0076] In the present application, the reference mirror is deleted. The guide vane 1 to be detected receives the measurement light beam 6 and the reference light beam 7 which are synchronously moved.

[0077] During the scanning process between the laser interferometer 4 and the guide vane 1 to be detected, although the relative displacement or the relative angle change still occurs, the optical path difference between the measurement light beam 6 and the reference light beam 7 is synchronously changed, and is almost not affected by the slight change in the position between the laser interferometer 4 and the guide vane 1 to be detected.

[0078] Further, during the scanning process, the problem of irregular jumps of interference imaging does not occur, so that the small damage position can be accurately scanned, and the scanning accuracy can be theoretically in the order of microns or even nanometers.

[0079] A transparent glass cylinder 10 filled with an internal pressure-adjustable gas is arranged on the optical path of the measurement light beam 6, and sulfur hexafluoride gas is filled into the transparent glass cylinder 10. By adjusting the pressure of the sulfur hexafluoride gas in the transparent glass cylinder 10, the refractive index is changed, and then the measurement light beam 6 and the reference light beam 7 produce standard interference to form a standard interference image which is easy to distinguish.

[0080] The scheme in the present application deletes the reference mirror, and the relative position adjustment of the laser interferometer 4 and the guide vane 1 to be detected is used to adjust the interference image. This is extremely complex, time-consuming, and difficult, and it is almost impossible to achieve by moving the macro mechanical scale to synchronously adjust the double light beams in the micron accuracy to present an ideal interference image.

[0081] In the patent application, the optical path of the single reference light beam 7 is adjusted extremely accurately by adjusting the gas pressure.

[0082] Based on the change relationship between the refractive index and the pressure, the pressure control precision of the gas pump in the prior art, and the relatively large size of the transparent glass cylinder 10 used in the patent, the optical path difference precision adjustment can reach the nanometer level.

[0083] First, the adjustment process becomes extremely simple and fast, and ordinary staff can easily operate and implement it.

[0084] Second, the adjustment level of the optical path difference is accurately adjusted to the nanometer level, which is beyond the reach of macro mechanical adjustment, providing a higher level of measurement basis for accurate measurement.

[0085] Moreover, the relative position of the laser interferometer 4 and the guide vane 1 to be detected is not moved during the adjustment process. It should be noted that under the measurement precision of microns, it is extremely difficult to adjust the interference image through macro mechanical scale movement.

[0086] The laser interferometer 4 in the above design is also provided with an optical collimation system and an optical component system.

[0087] The two reflected light beams enter the light shielding channel, and the light beams with a close-to-parallel direction to the light shielding channel pass through the light shielding channel. The light beams with a large angle difference are absorbed by the black frosted structure. By setting the inner wall of the light shielding channel as a black frosted structure, stray light is absorbed, multiple reflections are suppressed, and the light shielding channel only allows light beams propagating along the axis direction of the light shielding channel to pass through. Light beams with a large angle difference are blocked by the wall, and the black frosted inner wall of the straight circular tube absorbs the deviated light beams hitting the wall, reducing the influence of stray light on interference imaging.

[0088] The optical component system is formed by combining optical fibers and converging lenses. The light outlet of the light shielding channel is opposite to the light inlet of the optical fiber, and the converging lens is located behind the light outlet of the optical fiber. The reflected light beams passing through the light shielding channel enter the optical fiber through the light inlet of the optical fiber and then pass out of the light outlet of the optical fiber. After passing through the converging lens, the light beams are projected onto the grating.

[0089] The optical component system can also be formed by combining a mirror and a converging lens. The mirror is located behind the light shielding channel. The reflected light beams passing through the light shielding channel are reflected by the mirror to form a light beam. The converging lens is located on the light path of the light beam. After passing through the converging lens, the light beam is projected onto the grating.

[0090] In use, the following process is adopted:

[0091] S1: Place the guide vane 1 to be detected on the support 2.

[0092] S2: The blue light scanning detection system comprises a blue light scanner 3, which projects a blue light fringe onto the surface of the guide vane 1 to be detected to obtain three-dimensional topographic data of the surface of the guide vane 1 to be detected;

[0093] S3: The obtained three-dimensional topographic data is compared with the design data, and the deviation part is marked as a suspected problem area;

[0094] S4: The laser interferometer 4 is moved to the side of the suspected problem area, so that the reference light beam 7 and the measurement light beam 6 are focused on the smooth and intact surface beside the suspected problem area;

[0095] S5: The air pressure in the transparent glass cylinder 10 is adjusted to change the refractive index, thereby correcting the optical path difference to obtain a standard interference image;

[0096] S6: The laser interferometer 4 is horizontally rotated to move the reference light beam 7 and the measurement light beam 6 synchronously to scan the guide vane 1 to be detected to obtain a plurality of groups of measurement interference images;

[0097] S7: The measurement interference images are compared with the standard interference image, and when a change exceeding a set threshold is detected in the interference images, a defect point is marked.

[0098] The smooth and intact surface beside the suspected problem area is a surface area of the guide vane 1 to be detected within 5mm of the edge of the suspected problem area and within the allowable tolerance of the three-dimensional topographic data and the design data detected by the blue light scanner 3.

[0099] The interference fringes of the standard interference image need to be clear, continuous, high-contrast, and alternating light and dark fringes, and within a one-second collection time, the interference fringes do not have sharp jumps or blurring, and the interference images meeting the above conditions are standard interference images.

[0100] The laser interferometer 4 has a measurement light beam exit port for transmitting the measurement light beam 6 and a reference light beam exit port for transmitting the reference light beam 7; the measurement light beam exit port and the reference light beam exit port also serve as light entrance ports for reflected light rays. In order to guide the measurement light beam 6 and the reference light beam 7 to project onto two different and specific points on the surface of the guide vane 1 to be detected, and prevent the measurement light beam 6 and the reference light beam 7 from overlapping.

[0101] The length of the light shielding channel is 5cm~10cm, and the aperture is 0.5cm~1cm. The length and aperture of the light shielding channel can effectively block stray light and improve the stability of the reflected light rays during transmission, thereby improving the measurement accuracy and reliability.

[0102] The laser interferometer 4 is fixed on the holder 9, and the lower surface of the holder 9 is connected with a hydraulic rod 8 for controlling the vertical lifting of the holder 9. The laser interferometer 4 is provided with the working conditions of vertical movement and horizontal rotation through the hydraulic rod 8 and the holder 9, and the laser interferometer 4 always keeps stable during movement.

[0103] The transparent glass cylinder 10 is in a sealed structure, and the end faces of the two ends of the transparent glass cylinder 10 are flat; the end faces of the two ends of the transparent glass cylinder 10 are perpendicular to the direction of the light path of the measuring light beam 6.

[0104] The gas pump 11 and the sulfur hexafluoride gas source are further included; the transparent glass cylinder 10 is provided with a gas supply port for communicating the inside and outside of the transparent glass cylinder 10; the gas supply port is connected with the gas pump 11, the gas pump 11 is connected with the sulfur hexafluoride gas source, the gas pump 11 fills or extracts the sulfur hexafluoride gas into the transparent glass cylinder 10, so as to adjust the gas pressure in the transparent glass cylinder 10. The pressure of the sulfur hexafluoride in the transparent glass cylinder is adjusted through the gas pump 11, the physical characteristics that the speed of light in air is greater than that in sulfur hexafluoride are utilized, the optical path of the single reference light beam 7 is accurately adjusted, the standard interference image is obtained, and the transparent glass cylinder is connected with a gas pressure sensor for detecting the gas pressure in the transparent glass cylinder.

[0105] When the gas concentration of the sulfur hexafluoride is increased by 10 times, the refractive index of light is about 1.0087, and the speed of light is 2.973*108 m / s. The difference between the speed of light in the ordinary state is 0.0257*108 m / s, if the distance between the two ends of the transparent glass cylinder is 10 cm, then the reflection part of the guide vane to be detected is displaced by 0.39 mm, a large amount of gas adjustment can be achieved, high-precision optical path difference adjustment is realized, and the precision of the obtained interference image is higher.

[0106] The inner cavity cross-sectional area of the transparent glass cylinder is greater than 5 square centimeters and less than 10 square centimeters.

[0107] In use, the staff fixes the guide vane 1 to be detected vertically and stably on the support 2, turns on the blue light scanner 3, and the blue light scanner 3 projects a blue light stripe on the surface of the guide vane 1 to be detected, so as to obtain the three-dimensional topographic data of the surface of the guide vane 1 to be detected. The blue light scanning detection system compares the obtained three-dimensional topographic data with the design data, and marks the deviation part as a suspected problem area.

[0108] Then, the hydraulic rod 8 and the holder 9 are cooperated to provide power, so that the laser interferometer 4 moves to the side of the suspected problem area. First, the measuring light beam is projected on the smooth and intact surface beside the suspected problem area. The physical characteristics that the speed of light in air is greater than that in sulfur hexafluoride are utilized, the gas pump 11 adjusts the pressure of the sulfur hexafluoride in the transparent glass cylinder 10, the gas pressure sensor measures the gas pressure to obtain the pressure of the sulfur hexafluoride in the transparent glass cylinder 10, the measurement precision is improved, and the standard interference image is obtained.

[0109] The cloud platform 9 makes the laser interferometer 4 slowly and smoothly rotate horizontally, so that the reference light beam 7 and the measurement light beam 6 move synchronously, the guide vane 1 to be detected is scanned, a plurality of groups of measurement interference images are obtained, the measurement interference images are compared with the standard interference images, and when a change exceeding a set threshold is detected in the interference images, a defect point is marked.

[0110] The basic principles and main features of the application and the advantages of the application are shown and described above. Those skilled in the art should understand that the application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only illustrative of the principles of the application. Without departing from the spirit and scope of the application, various changes and improvements can be made to the application, and these changes and improvements all fall within the scope of the claimed application. The scope of the application is defined by the appended claims and their equivalents.

Claims

1. A combined vane surface inspection apparatus comprising a blue light scanning inspection system and a support (2) for loading a vane (1) to be inspected, characterised in that: The to-be-detected guide vane (1) is vertically placed; Further comprising a laser interferometer (4); The laser interferometer (4) comprises a laser, a beam splitter (5), and a grating, the beam splitter (5) divides an incident light beam into a measurement light beam (6) and a reference light beam (7); A transparent glass cylinder (10) containing an internal pressure-adjustable gas is arranged on the light path of the measurement light beam (6); The included angle between the measurement light beam (6) and the reference light beam (7) in the vertical direction is greater than 30° and less than 90°; Further comprising an optical collimation system, the optical collimation system comprising two light-shielding channels parallel to the pointing directions of the measurement light beam (6) and the reference light beam (7) respectively; The inner wall of the light-shielding channel adopts a straight circular tube-shaped inner wall with a black frosted structure; An optical assembly system for adjusting the angle of light is arranged behind each of the two light-shielding channels; The two optical assembly systems adjust the returned light beams transmitted by the two light-shielding channels respectively and then perform interference; The to-be-detected guide vane (1) is located on the light paths of the measurement light beam (6) and the reference light beam (7); After the reference light beam (7) and the measurement light beam (6) are reflected by the surface of the to-be-detected guide vane (1), two reflected light beams are formed, the reflected light beams filtered by the light-shielding channels enter the optical assembly system, are projected onto the grating, and an interference image is formed; The reference light beam (7) and the measurement light beam (6) are aligned with the intact area on the surface of the to-be-detected guide vane (1) to obtain a standard interference image; The laser interferometer (4) is horizontally rotated and displaced upward and downward to move the reference light beam (7) and the measurement light beam (6) synchronously, and the to-be-detected guide vane (1) is scanned, and when a change exceeding a set threshold value is detected in the interference image, a defect point is marked.

2. The combined wicket gate surface inspection apparatus of claim 1, wherein: The two reflected light beams enter the light-shielding channel, the light nearly parallel to the pointing direction of the light-shielding channel passes through the light-shielding channel, and the light with a large difference angle is absorbed by the black frosted structure.

3. The combined wicket gate surface inspection apparatus of claim 1, wherein: In use, the following process is adopted: S1: The to-be-detected guide vane (1) is arranged on the support (2); S2: The blue light scanning detection system comprises a blue light scanner (3), the blue light scanner (3) projects a blue light stripe onto the surface of the to-be-detected guide vane (1), and three-dimensional topographic data of the surface of the to-be-detected guide vane (1) is obtained; S3: The obtained three-dimensional topographic data is compared with design data, and a deviation part is marked as a suspected problem area; S4: The laser interferometer (4) is moved to the side of the suspected problem area, and the reference light beam (7) and the measurement light beam (6) are focused on the smooth intact surface beside the suspected problem area; S5: The air pressure in the transparent glass cylinder (10) is adjusted to change the refractive index and then correct the optical path difference, and a standard interference image is obtained; S6: The laser interferometer (4) is horizontally rotated to move the reference light beam (7) and the measurement light beam (6) synchronously, and the to-be-detected guide vane (1) is scanned to obtain a plurality of groups of measurement interference images; S7: The measurement interference images are compared with the standard interference image, and when a change exceeding a set threshold value is detected in the interference image, a defect point is marked.

4. The combined wicket gate surface inspection apparatus of claim 1, wherein: The laser interferometer (4) has a measurement light beam exit port through which the measurement light beam (6) is transmitted and a reference light beam exit port through which the reference light beam (7) is transmitted; The measuring beam outlet and the reference beam outlet also respectively serve as the light inlets of the reflected light.

5. The combined wicket gate surface inspection apparatus of claim 1, wherein: The length of the light-shielding channel is 5-10 cm, and the aperture is 0.5-1 cm.

6. The combined wicket gate surface inspection apparatus of claim 1, wherein: The laser interferometer (4) is fixed on the holder (9), and the lower surface of the holder (9) is connected with a hydraulic rod (8) for controlling the vertical lifting of the holder (9).

7. The combined wicket gate surface inspection apparatus of claim 1, wherein: The transparent glass cylinder (10) is in a sealed structure, and the end faces of the two ends of the transparent glass cylinder (10) are flat. The end faces of the two ends of the transparent glass cylinder (10) are perpendicular to the light path direction of the measuring beam (6).

8. The combined wicket gate surface inspection apparatus of claim 7, wherein: The gas pump (11) and the sulfur hexafluoride gas source are further included. The transparent glass cylinder (10) is provided with a gas supply port for communicating the inside and outside of the transparent glass cylinder (10). The gas supply port is connected with the gas pump (11), the gas pump (11) is connected with the sulfur hexafluoride gas source, and the gas pump (11) fills or extracts the sulfur hexafluoride gas into or out of the transparent glass cylinder (10), so as to adjust the gas pressure in the transparent glass cylinder (10).

9. The combined wicket gate surface inspection apparatus of claim 8, wherein: The inner cavity cross-sectional area of the transparent glass cylinder is greater than 5 square centimeters and less than 10 square centimeters.

Images