In-situ detection probe for blade tenon of aero-engine

Abstract

The invention relates to the technical field of nondestructive testing, in particular to an aero-engine blade tenon in-situ detection probe which enters from a probe hole, extends into a tenon part through a narrow gap between two blades and detects the inner side face of the tenon part, and comprises a handle, a probe rod, a video head and an eddy current detection sensor. The probe rod comprises first, second, third and fourth rod sections which are connected in sequence; the first rod section and the second rod section are hard supporting rods, and the third rod section and the fourth rod section are elastic sheets. The rod sections are bent and connected at a specific angle; wherein the first rod section is horizontally arranged, and the third rod section is vertically arranged; a reflecting film layer is arranged on the upper surface of the fourth rod section to form a reflecting mirror surface; the video head is slidably arranged on the third rod section through a slip ring structural member and is used for acquiring an image of the measured surface formed by reflection on the fourth rod section; and an elastic card type array eddy current detection sensor is arranged at the tail end of the fourth rod section for array eddy current detection. According to the invention, in-situ detection of the inner side surface of the blade tenon in a narrow detection path is realized.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing, and in particular to an in-situ detection probe for a tenon of an aero-engine blade. Background Art

[0002] Aircraft engines are the heart of modern aircraft, and their safety is a matter of great concern to the industry in every country. Blade fatigue damage is one of the important causes of aircraft accidents. However, due to the extremely complex structure of aircraft engines, it is not easy to achieve in-situ detection, especially the narrow detection space, which increases the difficulty. Figure 1 When inspecting the engine blade tenon, the final path from the casing to the inspection surface must pass through the narrow gap between the two blades, and then bend to the inspection surface. In the past, the endoscope inspection method was difficult to reach into, making it difficult to observe the entire inspection surface, and this inspection method is also difficult to effectively detect tiny cracks with almost no width. Based on this, the present invention improves on the existing technology and strives to achieve effective inspection. Summary of the invention

[0003] In order to solve the above problems, the present invention provides an aero-engine blade tenon in-situ detection probe, which is implemented as follows:

[0004] An in-situ detection probe for the tenon of an aircraft engine blade. The detection probe enters from a detection hole reserved on the aircraft engine, extends into the tenon through a narrow gap between two blades, and detects the inner side thereof. The detection probe includes a handle, a probe rod, a video head, and an eddy current detection sensor:

[0005] The probe rod comprises a first rod segment, a second rod segment, a third rod segment and a fourth rod segment which are connected in sequence; the first rod segment and the second rod segment are rigid support rods, and the third rod segment and the fourth rod segment are elastic sheets;

[0006] The first rod segment and the second rod segment are bent and connected at a fixed bending angle; a fixed connection angle is formed between the third rod segment and the fourth rod segment;

[0007] The first rod segment is arranged horizontally, and the third rod segment is arranged vertically;

[0008] The upper surface of the fourth rod segment is provided with a reflective film layer to form a reflective mirror surface;

[0009] The video head is slidably arranged on the third rod segment through a slip ring structure, and is used to obtain the image of the measured surface formed by reflection in the reflection mirror surface on the fourth rod segment;

[0010] The eddy current detection sensor is an elastic card array eddy current detection sensor and is arranged at the end of the fourth rod segment.

[0011] Furthermore, the connection angle between the third rod segment and the fourth rod segment is 135°.

[0012] Furthermore, an LED fill light source is also arranged on the slip ring structure.

[0013] Compared with the existing technology, this application can obtain the following technical effects:

[0014] The present invention proposes an in-situ detection probe with a special structure for detecting the inner side of the tenon of an engine blade in a narrow detection path. The in-situ detection probe structure of the present invention uses an elastic card-type array eddy current detection sensor and a video head for comprehensive detection, and uses a hard support rod combined with an elastic thin plate to form a multi-section bent probe rod. The bending angle of the rod section is reasonably designed, and a reflective film layer is plated on the elastic thin plate to form a reflective mirror surface for image reflection of the measured surface. In this way, the in-situ detection probe can be extended into a narrow gap to detect the inner side of the tenon, and video detection can be achieved by using reflection to comprehensively determine whether a defect exists and specifically determine the location of the defect. Compared with the existing technology, the present invention realizes effective detection of the inner side of the tenon of an engine blade in an in-situ state in a narrow detection path, and improves the reliability of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the examples of the present invention or the technical solutions in the prior art or the drawings required for use in the description of the prior art, a brief introduction is given. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a simplified structural diagram of the relative positions of the exploration holes and blades on the engine.

[0017] Figure 2 This is a schematic diagram of the structure of the engine blade.

[0018] Figure 3 It is a simplified structural schematic diagram of the in-situ detection probe of the present invention.

[0019] Figure 4 It is a schematic diagram of the arrangement of the array eddy current coils on the eddy current detection sensor of the present invention.

[0020] In the figure:

[0021] 10-in-situ detection probe, 11-first rod segment, 12-second rod segment, 13-third rod segment, 14-fourth rod segment; 15-handle, 16-eddy current detection sensor, 17-video head, 18-slip ring structure;

[0022] 20-tenon, 21-inner side, 22-crack, 23-narrow gap between two leaves;

[0023] 30-Exploration hole. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but only represents selected embodiments of the present invention.

[0025] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0026] The structure of aircraft engines is extremely complex. In-situ detection of their internal structures often requires overcoming multiple levels of limiters, which brings great difficulty to the health detection of the structure. In particular, for the detection of the inner side of the tenon of the second or higher turbine blades, it is necessary to extend the probe rod from the probe hole, pass through the narrow gap between the two blades, and then bend to the inner side. In the traditional non-destructive testing of the internal structure of the engine, endoscopes are usually used for detection. However, due to the complex detection conditions, this method is difficult to extend into the blade gap for complete observation of the inner side, and this method cannot observe tiny cracks with almost no width. The present invention studies a new type of in-situ detection probe, which adopts elastic card array eddy current detection combined with video detection and special probe rod structure design, aiming to effectively detect this special detection condition.

[0027] An in-situ detection probe for the tenon of an aircraft engine blade. The detection probe 10 enters from a detection hole 30 reserved on the aircraft engine, extends into the tenon 20 through a narrow gap 23 between two blades, and detects the inner side 21 thereof. The detection probe 10 includes a handle 15, a probe rod, a video head 17, and an eddy current detection sensor 16:

[0028] The probe rod includes a first rod segment 11, a second rod segment 12, a third rod segment 13, and a fourth rod segment 14 which are connected in sequence; the first rod segment 11 and the second rod segment 12 are rigid support rods, and the third rod segment 13 and the fourth rod segment 14 are elastic sheets; the elastic sheet enables the probe rod to flexibly extend into the narrow gap between the two blades.

[0029] The first rod segment 11 and the second rod segment 12 are bent and connected at a fixed bending angle, and a circular arc chamfer is provided at the bending connection of the first rod segment 11 and the second rod segment 12, so as to facilitate the insertion of the probe rod and adapt to the complex structure inside the engine; a fixed angle of connection is formed between the third rod segment 13 and the fourth rod segment 14;

[0030] The first rod segment 11 is arranged horizontally, and the third rod segment 13 is arranged vertically;

[0031] The upper surface of the fourth rod segment 14 is provided with a reflective film layer to form a reflective mirror surface;

[0032] The video head 17 is slidably set on the third rod segment 13 through a slip ring structure 18, and is used to obtain the image of the measured surface formed by reflection in the reflective mirror on the fourth rod segment 14; the third rod segment 13 is vertically set, and the camera angle of the video slidably set on the third rod segment 13 is perpendicular to the narrow gap between the two blades. When the detection probe moves up and down for scanning, the video head slides relative to the third rod segment 13 through the slip ring structure, and the video head always maintains a fixed distance from the upper end of the blade gap to ensure the stability of image acquisition.

[0033] The eddy current detection sensor 16 is an elastic card-type array eddy current detection sensor and is arranged at the end of the fourth rod segment 14. The elastic card-type array eddy current detection sensor is convenient for passing through exploration holes and narrow gaps. At the same time, the elastic card-type array eddy current detection sensors lined up in a row can better fit the measuring surface for rapid scanning and imaging.

[0034] During the inspection, hold the handle and insert the probe rod through the probe hole. The inspector moves the probe rod according to the real-time image of the engine inside obtained by the video head, and extends the third rod segment 13 and the fourth rod segment made of elastic thin plate into the tenon 20 along the narrow gap 23 between the two blades. The third rod segment 13 and the fourth rod segment 14 and the elastic card array eddy current detection sensor set at the end of the fourth rod segment 14 are reset to the original angle, and the elastic card array eddy current detection sensor is attached to the surface to be tested, and scanned up and down to capture the overall contour information of the surface to be tested and the fatigue crack information on its surface. At the same time, the image of the surface to be tested is formed by reflection in the reflective mirror on the fourth rod segment 14, and the video head set vertically on the gap between the two blades obtains the reflected image of the surface to be tested.

[0035] Furthermore, the elastic card array eddy current detection sensor can automatically detect whether the sensor is in contact with the measured surface according to the lift-off situation, and the instrument can perform lift-off compensation to improve the reliability of the detection.

[0036] Furthermore, an LED fill light source is also provided on the slip ring structure 18 .

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An in-situ detection probe for the tenon of an aircraft engine blade, wherein the detection probe enters from a detection hole reserved on the aircraft engine, extends into the tenon through a narrow gap between two blades, and detects the inner side thereof. The detection probe comprises a handle, a probe rod, a video head, and an eddy current detection sensor, and is characterized in that: The probe rod comprises a first rod segment, a second rod segment, a third rod segment and a fourth rod segment which are connected in sequence; the first rod segment and the second rod segment are rigid support rods, and the third rod segment and the fourth rod segment are elastic sheets; The first rod segment and the second rod segment are bent and connected at a fixed bending angle; a fixed connection angle is formed between the third rod segment and the fourth rod segment; The first rod segment is arranged horizontally, and the third rod segment is arranged vertically; The upper surface of the fourth rod segment is provided with a reflective film layer to form a reflective mirror surface; The video head is slidably arranged on the third rod segment through a slip ring structure, and is used to obtain the image of the measured surface formed by reflection in the reflection mirror surface on the fourth rod segment; The eddy current detection sensor is an elastic card array eddy current detection sensor and is arranged at the end of the fourth rod segment.

2. The in-situ detection probe for aero-engine blade tenon according to claim 1, characterized in that: The connection angle between the third rod segment and the fourth rod segment is 135°.

3. The in-situ detection probe for aero-engine blade tenon according to claim 1, characterized in that: An LED fill light source is also arranged on the slip ring structure.

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