Three-dimensional optical measurement method for blade profile of high-pressure integral blade ring

Abstract

The invention provides a three-dimensional optical measurement method for a high-pressure integral blade ring blade profile, which is used for spraying a developing agent on the surface of an integral blade ring, especially on the air inlet and exhaust edges, so as to realize three-dimensional optical measurement of the high-pressure closed integral blade ring blade profile. Spraying a developing agent on the surface of the part before measurement; in order to improve the scanning quality of the high-pressure integral blade ring blade profile, especially the air inlet and exhaust edge, a mixture of titanium dioxide and industrial alcohol is adopted for spraying; a special tool clamp is designed, a part is connected with an optical measuring machine, the automatic centering function is achieved, and a measuring head can conveniently collect data on the upper portion and the lower portion of the integral blade ring. And optically scanning integral blade ring blade profile surface data. The method has the advantages that the three-dimensional optical automatic measurement of the high-pressure integral blade ring is realized, the blade profile measurement precision of the high-pressure integral blade ring is improved, the efficiency is improved by more than 50%, and the method can be popularized to the measurement of the integral blade ring of the fan, and has wide market prospects and huge economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of integral blade ring measurement, and in particular to a three-dimensional optical measurement method for a high-pressure integral blade ring blade profile. Background Art

[0002] The high-pressure integral bling, located at the high-pressure compressor end of an engine, features a complex blade profile and thinner edges. This, combined with its double-edge plate structure, presents significant inspection challenges. Conventional 3D optical measurement methods require attaching splicing positioning reference points to the part surface. The edge data scan quality is inconsistent, resulting in unreliable measurement accuracy and an inability to accurately represent the actual state of the bling profile. Summary of the Invention

[0003] The present invention summarizes and establishes a three-dimensional optical measurement method for the high-pressure integral blade ring profile of an aircraft engine. The method adopts a three-dimensional optical measurement process, determines the developer spraying parameters and optical scanning parameters before part measurement, and designs a special measurement tool, thereby realizing three-dimensional optical measurement of the high-pressure integral blade ring profile and improving measurement accuracy and efficiency.

[0004] The present invention provides a three-dimensional optical measurement method for the blade profile of a high-pressure integral blade ring. Before the optical measurement of the high-pressure integral blade ring, the present invention sprays the surface of the integral blade ring, especially the intake and exhaust edges, with a developer, selects appropriate optical measurement parameters, and cooperates with special measuring tooling to achieve three-dimensional optical measurement of the blade profile of a high-pressure closed integral blade ring.

[0005] (1) Spray developer on the part surface before measurement

[0006] In order to improve the high-pressure and high-pressure integral blade ring blade profile, especially the scanning quality of the intake and exhaust edges, a mixture of titanium dioxide and industrial alcohol is used for spraying. The number of spraying times does not exceed 5 times, and the visual coverage rate reaches more than 100%.

[0007] (2) Design and application of special measuring tooling

[0008] In order to avoid sticking reference points on the surface of the part, fix the part and facilitate the optical probe to adjust the measurement posture, a special tooling fixture is designed to connect the part to the optical measuring machine. It has an automatic centering function, which facilitates the probe to collect data on the upper and lower parts of the integral blade ring.

[0009] The tooling consists of a support column assembly, a support cover assembly, a large circular ring for attaching points, an external center adjustment assembly, a small circular ring for attaching points, an internal center adjustment assembly, a fixed angle structure, and a scale positioning assembly; the support column assembly includes a column, a bottom connecting plate, and a top connecting structure; the support cover assembly includes a support arm and a connecting block; the external center adjustment assembly includes an axial positioning structure and a radial clamping structure. The internal centering assembly includes an axial positioning structure and a radial clamping structure. The scale positioning assembly includes a scale mounting groove, a clamping device, and a lifting ring. The support column assembly is connected to the equipment turntable by bolts, and the top connecting structure and the support cover assembly are clearance-fitted and connected with angular bolts. The parts are placed on the axial positioning plate of the internal centering assembly, and the knob is adjusted so that the parts, tooling, and turntable are on the same rotating axis. Adjust the external center adjustment assembly to the appropriate position, such as Figure 1 shown.

[0010] (3) Optical scanning of the entire blade ring blade surface data

[0011] According to the requirements of high-pressure integral blade ring measurement accuracy, the appropriate optical lens group and standard scale are selected, the scanning probe path is compiled, and the appropriate scanning process parameters are set to obtain the three-dimensional data of the high-pressure integral blade ring surface.

[0012] Advantages of the present invention:

[0013] The high-pressure integral blade ring blade profile three-dimensional optical measurement method described in the present invention adopts the measurement method described in this patent to realize the three-dimensional optical automatic measurement of the high-pressure integral blade ring, and improve the measurement accuracy of the high-pressure integral blade ring blade profile, with the efficiency increased by more than 50%. It can be extended to the measurement of the integral blade ring of the fan, and has broad market prospects and huge economic benefits.

[0014] Figures in the specification

[0015] Figure 1 Schematic diagram of the special fixture;

[0016] Figure 2 Assembly drawing of the integral blade ring 3D optical measurement fixture;

[0017] Figure 3 Schematic diagram of the hexagonal ring structure;

[0018] Figure 4 Schematic diagram of the centering assembly and angular orientation structure with graduated scale lines;

[0019] Figure 5 Schematic diagram of the ruler positioning component;

[0020] Figure 6 Paste reference points and code points;

[0021] Figure 7 Schematic diagram of spraying developer;

[0022] Figure 8 Schematic diagram of measurement fixture and measurement path simulation;

[0023] In the figure, there are support column assembly 1, support cover assembly 2, large sticking ring 3, circumcenter adjustment assembly 4, small sticking ring 5, inner centering assembly 6, angular structure 7, and scale positioning assembly 8. DETAILED DESCRIPTION

[0024] The present invention will be further explained below in conjunction with specific implementation plans, but the present invention is not limited thereto. The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0025] (1) Select appropriate measuring equipment

[0026] Taking a high-pressure integral blade ring with a diameter of 510mm and 101 blades as an example, a measuring machine with accuracy that meets the requirements is selected. Taking into account the characteristic that the radius of the blade intake and exhaust edges is about 0.2mm, the imaging grid pixel spacing is selected to be less than 0.05mm to ensure that the edge imaging points are not less than 12. The shape error of the selected lens group is ≤0.002mm; the size error is ≤0.004mm; the ball spacing error is ≤0.006mm, and the reference point is a 0.8mm special measurement reference point and a 2.5mm coding point. The measuring machine has path simulation function.

[0027] (2) Paste reference points and coding points

[0028] Special reference points and coding points are affixed to the surface of the large and small sticking rings and ruler positioning components on the tooling to ensure that within any 170x130x110mm measurement volume, there are at least 8 reference points and at least 3 coding points. Figure 6 shown.

[0029] (3) Special developer for spraying on parts surface

[0030] Wipe the surface of the nozzle ring part to be tested to remove dirt and keep the surface of the part clean and dry. Transport the treated parts to the powder spraying room for powder spraying treatment. Use industrial alcohol and special titanium dioxide powder (diameter less than 0.001mm, particles are not easy to stick together) in a ratio of 1:10 to 1:15 to make a developer. The nozzle is 200-300mm away from the part surface. The spraying speed is not more than 0.2m / s, the edge is not more than 0.1m / s, and the number of spraying times in the same area is not more than 3 times. The spraying range should cover the part to be tested and the measurement reference part. Visually check the developer coverage of the part surface, which should be greater than 100%. Figure 7 As shown, after powder spraying, it is clamped on a special tooling.

[0031] (4) Installation and adjustment of tooling

[0032] Clamp the special fixture on the measuring machine turntable. First, align the four holes of the fixture chassis with the four threaded holes of the measuring machine turntable. At the same time, align the position of the angular bolt hole in the fixture with the mark X1 on the turntable scale line, and tighten the angular bolts. Install the part on the measuring fixture. Pay attention to touch the inner ring of the part as much as possible with your hands, and do not touch the powder-sprayed part to avoid damaging the powder-spraying state. Install the scale in the mounting slot on the top of the fixture. Figure 8 shown.

[0033] (5) Measurement trajectory planning

[0034] When shooting, it is recommended to shoot the scale position first, and use the turntable to measure at the same time, rotating the shooting fixture and scale points from top to bottom at different tilt angles. Use the scanning measurement series to scan single or several blades. The binocular connection line of the measuring head is basically parallel to the blade intake and exhaust. When shooting the intake and exhaust edges, the measuring head is slightly tilted by about 20°-40°, and then shoot the edge at multiple angles along the edge as the axis. The scanning parameters can select more points to improve the stability of the point collection and avoid the lack of point collection in some places due to uneven powder spraying. After the trajectory is generated, run the automatic collection program as follows Figure 8 shown.

[0035] (6) Measure the quality of the 3D data grid

[0036] After completing a data collection, the measured point cloud is meshed. When the point cloud data is too large to be handled manually, the median filter method is used to smooth the mesh to generate the three-dimensional data of the measured part. The mesh quality is checked to see if there are any defects such as missing points or folded points on the mesh surface. Repeat steps 5 and 6 above until the mesh data is complete and smooth.

[0037] (7) Overall blade ring profile data analysis

[0038] Import the entire blade ring model into the software, establish a benchmark according to the drawing requirements, and align the theoretical model with the actual test model by aligning geometric elements or surface-line-point. Calculate and evaluate the blade section parameters based on the test process.

[0039] Matters not covered by the present invention are known technologies.

[0040] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional optical measurement method for high-pressure integral blade ring blade profile, characterized by: Before the optical measurement of the high-pressure integral blade ring, the surface of the integral blade ring, especially the intake and exhaust edges, is sprayed with developer to achieve three-dimensional optical measurement of the blade profile of the high-pressure closed integral blade ring; (1) Spray developer on the surface of the part before measurement; In order to improve the high-pressure and high-pressure integral blade ring profile, especially the scanning quality of the intake and exhaust edges, a mixture of titanium dioxide and industrial alcohol is sprayed. The number of spraying times does not exceed 5 times, and the visual coverage rate reaches more than 100%; (2) Design and application of special measuring tooling; In order to avoid sticking reference points on the part surface, fix the part and facilitate the optical probe to adjust the measurement posture, a special fixture is designed to connect the part to the optical measuring machine. It has an automatic centering function, which facilitates the probe to collect data from the upper and lower parts of the integral blade ring. (3) Optical scanning of the entire blade ring blade surface data; According to the requirements of high-pressure integral blade ring measurement accuracy, the appropriate optical lens group and standard scale are selected, the scanning probe path is compiled, and the appropriate scanning process parameters are set to obtain the three-dimensional data of the high-pressure integral blade ring surface.

2. The three-dimensional optical measurement method for high-pressure integral baffle profile according to claim 1, characterized in that: The special fixture consists of a support column assembly, a support cover assembly, a large circular ring for attaching points, an outer center adjustment assembly, a small circular ring for attaching points, an inner center adjustment assembly, an angular structure, and a scale positioning assembly; the support column assembly includes a column, a bottom connecting plate, and a top connecting structure; the support cover assembly includes a support arm and a connecting block; the outer center adjustment assembly includes an axial positioning structure and a radial pressing structure; the inner centering assembly includes an axial positioning structure and a radial pressing structure; The scale positioning assembly includes a scale mounting groove, a clamping device, and a lifting ring; the support column assembly is connected to the equipment turntable by bolts, the top connecting structure and the support cover assembly are fitted with clearance, and the angular bolts are tightened to connect, the parts are placed on the axial positioning plate of the inner centering assembly, the knob is adjusted so that the parts, tooling, and turntable are on the same rotating axis, and the excentric adjustment assembly is adjusted to the appropriate position.

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