A visual guidance based turbine blade film hole automatic measuring device

Abstract

The application discloses a kind of turbine blade film hole automatic measuring device based on visual guidance, it is related to turbine blade film hole measuring technical field, including three coordinate measuring machines, the mobile end of three coordinate measuring machines is respectively installed with sleeve and camera, probe is installed in sleeve, probe bottom extends outside sleeve, adjust camera angle, make the center point of camera and the center point of probe coincide, film pressure sensor is installed in sleeve, and film pressure sensor contacts probe.The application is identified to film hole by the combination of probe and camera, the function of automatic needle measurement is completed by visual guidance, manual visual inspection is not needed, and precision is high, time-saving and labor-saving;And three coordinate measuring machines are used to control the movement of probe, reduce cost, and convenient operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of turbine blade film hole measurement, and particularly relates to a turbine blade film hole automatic measurement device based on visual guidance. BACKGROUND

[0002] The turbine blade film hole needs corresponding measurement and calibration devices to detect its precision and quality control. However, due to the position of the film hole including hole spacing, row spacing, the hole itself including hole size, morphology, inner wall surface roughness and surface integrity and various data, the too complex data type of the film hole can only use contact or non-contact nondestructive testing technology.

[0003] At present, the film hole position measurement method adopted by the domestic aircraft engine blade factory is basically the visual comparison method. It is equivalent to measuring the surface roughness of the zero component by comparing the surface roughness of the sample block. Since there is no calibration specification for the hole position standard blade at present, and there is no instrument that can calibrate the position degree parameters, therefore, using the hole position standard blade without calibration as a physical standard for comparison measurement of the blade film hole position degree is not in line with the requirements of value traceability or transmission, therefore, this method can only be operated by experienced skilled workers, and the existing equipment has large measurement error by visual measurement, which is time-consuming and laborious and low in efficiency.

[0004] Therefore, there is an urgent need for a turbine blade film hole automatic measurement device based on visual guidance to solve the problems existing in the prior art. SUMMARY

[0005] The purpose of the present application is to provide a turbine blade film hole automatic measurement device based on visual guidance to solve the problems existing in the prior art.

[0006] To achieve the above purpose, the present application provides the following scheme: the present application provides a turbine blade film hole automatic measurement device based on visual guidance, comprising a three-coordinate measuring machine, a sleeve and a camera are installed at the moving end of the three-coordinate measuring machine respectively, a probe is installed in the sleeve, the probe bottom extends out of the sleeve, the angle of the camera is adjusted, so that the center point of the camera coincides with the center point of the probe, a thin film pressure sensor is installed in the sleeve, and the thin film pressure sensor is in contact with the probe.

[0007] Preferably, a partition plate is installed in the sleeve, the thin film pressure sensor is installed at the bottom end of the partition plate, and the top of the probe is in contact with the thin film pressure sensor.

[0008] Preferably, a hollow sphere is rotatably connected in the sleeve, and one end of the partition plate away from the thin film pressure sensor is fixedly connected with the inner wall of the hollow sphere.

[0009] Preferably, the hollow sphere is provided with a through hole at the bottom, and the probe is matched with the through hole.

[0010] Preferably, the sleeve is provided with an opening at the bottom, and the diameter of the opening is larger than the diameter of the probe, and the probe is inserted into the sleeve from the opening.

[0011] Preferably, the sleeve is provided with an external thread at the bottom, and the sleeve is detachably connected with a nut through the external thread, and the nut is used for fixing the probe.

[0012] Preferably, the moving end of the three-coordinate measuring machine is provided with a mounting frame, the top of the sleeve is fixedly connected with the mounting frame, and the camera is rotatably connected with the mounting frame, and the camera is located on one side of the sleeve.

[0013] The present application discloses the following technical effects: the present application combines the probe with the camera to identify the gas film hole, and realizes the function of automatic needle insertion measurement through visual guidance, without manual visual inspection, and with high precision, saving time and labor; and the three-coordinate measuring machine is used to control the movement of the probe, reducing the cost and being convenient to operate. BRIEF DESCRIPTION OF DRAWINGS

[0014] The drawings constituting a part of the present application are used to provide further understanding of the present application, the illustrative embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings:

[0015] Figure 1 is a structural schematic diagram of the present application;

[0016] Figure 2 is an assembly drawing of the sleeve and the nut of the present application;

[0017] Figure 3 is an internal structure schematic diagram of the sleeve of the present application;

[0018] Figure 4 is a recognition logic diagram of the gas film hole of the present application;

[0019] Figure 5 is a projection schematic diagram of the gas film hole of the present application;

[0020] Figure 6 is an assembly drawing of the AX4 sensor and the hollow sphere of the present application;

[0021] Figure 7 is a gas film hole recognition code flow chart of the present application;

[0022] Figure 8 is an assembly drawing of the camera and the mounting frame of the present application;

[0023] In the figure: 1, three coordinate measuring machine; 2, sleeve; 3, hollow sphere; 4, partition; 5, thin film pressure sensor; 6, through hole; 7, nut; 8, probe; 9, mounting bracket; 10, camera; 11, AX4 sensor. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0026] Embodiment one

[0027] Referring to Figures 1-8 The present embodiment provides a kind of automatic measurement device of turbine blade film hole based on visual guidance, including three coordinate measuring machine 1, the mobile end of three coordinate measuring machine 1 is respectively equipped with sleeve 2 and camera 10, probe 8 is installed in sleeve 2, probe 8 bottom extends out of sleeve 2, adjust the angle of camera 10, make the center point of camera 10 and the center point of probe 8 coincide, thin film pressure sensor 5 is installed in sleeve 2, and thin film pressure sensor 5 is in contact with probe 8.

[0028] Images are acquired by camera 10, and a classifier for detecting and recognizing film films is independently trained using the Python-OpenCV library. Visual guidance technology guides probe 8 to the center point of the film film film. During operation, the turbine blades are inspected via an S-shaped path. When camera 10 and the probe are inspecting the entire worktable, once camera 10 detects a film film film, the inspection stops, and the probe is guided to the area above the film film film. The X and Y axis data of the coordinate measuring machine 1 at this point are recorded as the X and Y axis coordinates of the film film film. The Z-axis guide rail of the coordinate measuring machine 1 is controlled to insert probe 8 into the film film film. When probe 8 moves upward under pressure, it ultimately applies a force to the thin-film pressure sensor 5. When the force on the thin-film pressure sensor 5 exceeds a certain value, this indicates… At this point, the Z-axis position of the probe 8 head is the Z-axis position of the film film aperture. Record the current position and use trigonometric functions to determine the normal angle. After completing the data collection of one film film aperture, return to the position of the film film aperture found by the camera 10 and continue to patrol the entire worktable to find the next film film aperture until the camera 10 has patrolled the entire worktable, which is convenient for subsequent carbon removal operations on the film film aperture. The film film apertures are distributed in various parts of the turbine blade. Since the surface of the turbine blade is curved, the angle of the axis of the film film aperture relative to the horizontal plane may be from -90° to 90°. However, the included angle between the film film apertures is rarely perpendicular. Therefore, when fixing the turbine blade, pay attention to the angle of the film film aperture and try not to be perpendicular to the direction of the camera 10 to prevent the camera 10 from failing to capture the image of the film film aperture.

[0029] This invention identifies air film pores by combining probe 8 with camera 10, and completes automatic pin measurement through visual guidance, eliminating the need for manual visual inspection, and achieving high accuracy, saving time and effort; in addition, the use of coordinate measuring machine 1 to control the movement of probe 8 reduces costs and makes operation convenient.

[0030] Furthermore, when the image of the air film aperture is elliptical, it indicates that the axis of the air film aperture has an angle other than 90° with the horizontal plane. Since the image of the air film aperture is the projection of a circular air film aperture onto the horizontal plane, it can be concluded that the longest radius of the ellipse is the same as the radius of the air film aperture; according to Figure 5 As shown, there is a geometric relationship between the length of the minor radius of the ellipse and the angle and length of the air film aperture. The sum of the angle between the projection of the air film aperture and the actual air film aperture, and the angle between the axis of the air film aperture and the horizontal plane, is 90°. Based on this relationship, after knowing the vertical values ​​of the major and minor radii in the elliptical image of the air film aperture projection, let the major radius be a and the minor radius be b. Then, according to the formula α = arccos(b / a), the angle α between the axis of the air film aperture and the horizontal plane can be obtained.

[0031] Further optimization scheme, the sleeve 2 is provided with a partition plate 4, the film pressure sensor 5 is installed at the bottom end of the partition plate 4, and the top of the probe 8 is in contact with the film pressure sensor 5. The partition plate 4 is used for installing and supporting the film pressure sensor 5.

[0032] Further optimization scheme, the hollow sphere 3 is rotatably connected in the sleeve 2, and the end, away from the film pressure sensor 5, of the partition plate 4 is fixedly connected with the inner wall of the hollow sphere 3.

[0033] Further, the AX4 sensor 11 is arranged above the hollow sphere 3, and the horizontal cut of the upper half of the hollow sphere 3 has a diameter of 20 mm, which is the same as the diameter of the spherical probe of the AX4 sensor 11; when the probe 8 is tilted due to force, the probe 8 will transmit the force to the hollow sphere 3, the hollow sphere 3 will rotate and transmit the force to the AX4 sensor 11.

[0034] The hollow sphere 3 has the following advantages in force transmission: the hollow sphere 3 can rotate in any direction, compared with the rod for transmitting force, the probe 8 will not be out of the hollow sphere 3 to cause failure; the sleeve 2 wall is tangent to the hollow sphere 3, so the hollow sphere 3 will not be stuck; the cut of the upper half of the hollow sphere 3 has the same diameter as the probe ball of the AX4 sensor 11, and the hollow sphere 3 and the probe need interference fit, so that the hollow sphere 3 will not be out of the part when changing the angle, the AX4 sensor 11 can detect the direction of the shear stress received, thereby helping to obtain the gas film hole method vector subsequently, and an indicating lamp can be added, so that the operator can more clearly confirm the stress condition of the probe 8, and can quickly respond when failure occurs, preventing damage to the part.

[0035] Further optimization scheme, the hollow sphere 3 is provided with a through hole 6 at the bottom, and the probe 8 is matched with the through hole 6. The through hole 6 in the lower half of the hollow sphere 3 has a diameter of 0.8, which is used to pass the probe 8.

[0036] Further optimization scheme, the sleeve 2 is provided with an opening at the bottom, the diameter of the opening is greater than the diameter of the probe 8, and the probe 8 extends into the sleeve 2 from the opening.

[0037] Further optimization scheme, the sleeve 2 is provided with an external thread at the bottom, the sleeve 2 is detachably connected with a nut 7 through the external thread, and the nut 7 is used for fixing the probe 8.

[0038] Further optimization scheme, the moving end of the three-coordinate measuring machine 1 is provided with a mounting frame 9, the top of the sleeve 2 is fixedly connected with the mounting frame 9, the camera 10 is rotatably connected with the mounting frame 9, and the camera 10 is located on one side of the sleeve 2.

[0039] Embodiment two

[0040] Different from the first embodiment, the center deviation problem is solved by code. Since the probe 8 and the camera 10 are parallel, when the camera 10 guides the probe 8 to the center of the air film hole, the center of the probe 8 cannot reach the center of the air film hole, but the distance between the probe 8 and the center of the air film hole is fixed, that is, the distance between the center of the probe 8 and the center of the camera 10, so only need to move the probe 8 to the direction of the camera 10 after the guidance of the camera 10 is completed, and the distance between the center of the probe 8 and the center of the camera 10 is compensated to achieve the guidance purpose. The advantage of this method is simple and direct, and there is no additional error.

[0041] Since the color difference between the air film hole and the turbine blade is large, the image of the air film hole collected by the camera 10 can be grayed, binarized, eroded and expanded. At this time, the picture area where the air film hole is located will become a black pixel. By edge detection method (which can be realized by code), the sum of the positions of all black pixels is divided by 2, and the center point of all black pixels, that is, the center position of the air film hole, is obtained.

[0042] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0043] The above-described embodiments are only preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope of the present application.

Claims

1. An automatic measurement device for film gas apertures of turbine blades based on vision guidance, characterized in that: The system includes a coordinate measuring machine (1), with a sleeve (2) and a camera (10) installed on the moving end of the coordinate measuring machine (1). A probe (8) is installed inside the sleeve (2), with the bottom of the probe (8) extending out of the sleeve (2). The angle of the camera (10) is adjusted so that the center point of the camera (10) coincides with the center point of the probe (8). A thin-film pressure sensor (5) is installed inside the sleeve (2), and the thin-film pressure sensor (5) is in contact with the probe (8). A partition (4) is installed inside the sleeve (2), the thin film pressure sensor (5) is installed at the bottom end of the partition (4), and the top of the probe (8) is in contact with the thin film pressure sensor (5); A hollow sphere (3) is rotatably connected inside the sleeve (2), and the end of the partition (4) away from the thin film pressure sensor (5) is fixed to the inner wall of the hollow sphere (3); The hollow sphere (3) has a through hole (6) at its bottom, and the probe (8) is adapted to the through hole (6). An AX4 sensor (11) is provided above the hollow sphere (3). The diameter of the horizontal cut of the upper half of the hollow sphere (3) is 20mm, which is the same as the diameter of the spherical probe of the AX4 sensor (11). When the probe (8) tilts due to force, the probe (8) will transmit the force to the hollow sphere (3), and the hollow sphere (3) will rotate and transmit the force to the AX4 sensor (11). The sleeve (2) has an opening at the bottom, the diameter of which is larger than the diameter of the probe (8), and the probe (8) extends into the sleeve (2) from the opening; The sleeve (2) has an external thread at the bottom, and the sleeve (2) is detachably connected to a nut (7) through the external thread. The nut (7) is used to fix the probe (8). The bottom of the moving end of the coordinate measuring machine (1) is provided with a mounting frame (9), the top of the sleeve (2) is fixedly connected to the mounting frame (9), the camera (10) is rotatably connected to the mounting frame (9), and the camera (10) is located on one side of the sleeve (2).

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