JPH0552757A - Inspecting apparatus of metallic fatigue or the like of narrow part - Google Patents

Abstract

PURPOSE:To obtain an inspecting apparatus of the metallic fatigue or the like of a narrow part of a structure showing the stress concentration without dismantling the structure. CONSTITUTION:This apparatus is provided with a flexible tube 3 and a flexible optical fiber scope 5. The flexible tube 3 has a spray nozzle 2 at the front end thereof to wipe away a fluorescent paint after the paint is sprayed to a to-be-inspected body. After the flexible tube 3 transfers the paint, it sends the air. The optical fiber scope 5 is provided with a photodetecting part 6 of arm optical system which is bound with the flexible tube 3 and arranged parallel to the spray nozzle 2. The remaining fluorescent paint after wiping is monitored by the flexible optical fiber scope 5. Moreover, a flexible ultraviolet radiation fiber 14 is bound with the flexible tube 3 and the optical fiber scope 5 to cast the ultraviolet light to the remaining fluorescent paint.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for inspecting metal fatigue by detecting minute cracks generated on the surface of a metal, and more particularly, to the inspection of a narrow space and stress concentration in an aircraft engine or pressure bulkhead. The present invention relates to a device for inspecting a metal fatigue in a narrow space, which can inspect a structure to be disassembled without disassembling it.

[0002]

2. Description of the Related Art In a metal structure having mechanical strength, if a fluctuating load or vibration is repeatedly applied for a long period of time, metal fatigue may occur depending on the magnitude and frequency of the stress. When metal fatigue occurs, it is easily destroyed, so structures that require safety, such as aircraft engines, pressure bulkheads, and nuclear equipment, must be inspected daily to check for metal fatigue. .. In order to check the presence / absence of metal fatigue of the structure used in this way, it is needless to say that nondestructive inspection is performed, but in aircraft, an inspection called fluorescent flaw detection is also performed in nondestructive inspection. Hereinafter, the conventional fluorescent flaw detection will be described.

Fluorescent flaw detection is to detect the presence or absence of metal fatigue by finding minute cracks (cracks) on the metal surface caused by metal fatigue, and is characterized by using fluorescence for finding cracks. .. The procedure of fluorescent flaw detection is to apply the fluorescent paint to the object to be inspected and then wipe it off.
Ultraviolet light is irradiated here. At this time, if there is a crack on the surface of the object to be inspected, the fluorescent paint will enter the crack and remain even after being wiped from the surface, so that fluorescence will be generated in response to the ultraviolet light. That is, only the cracked portion emits fluorescence. Therefore, the crack can be found by visually observing the shining portion. Generally, in order to make this visual work effective, it is performed by irradiating ultraviolet light with a black light or the like in a dark environment such as a dark room. As described above, when fluorescence is generated in a dark environment, it becomes easy to find even a minute fluorescence source, which brings an advantage of fluorescence flaw detection. Further, the crack thus found can be confirmed on the spot by marking a mark on the periphery with a visible paint and then under normal illumination.

[0004]

However, in the above-mentioned fluorescent flaw detection, there is a drawback that the efficiency is poor because the cracks are found in the dark room work.

Further, there is a problem that it is not preferable for an aircraft such as an aircraft which has a high operating rate and is frequently inspected, to remove the engine and the pressure bulkhead and bring them into a dark room because it takes time.

Further, since the fluorescent source is to be found by visual observation, there is a drawback that a narrow portion, a bent portion, or the like that cannot be seen cannot be examined.

In the structure, stress concentration is particularly likely to occur at the corners such as the joints and the rising portions, and the metal fatigue inspection is required accordingly. However, the corners are also narrow portions and bent portions at the same time. However, the inability to see this was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an inspection device for a metal fatigue of a narrow space, which can inspect a structure having a narrow space and stress concentration without disassembling.

[0009]

In order to achieve the above object, the present invention has a spray nozzle at the tip end to spray the fluorescent paint applied to an object to be inspected and then wipes the applied fluorescent paint. A flexible tube for transferring the paint and then the air, and a flexible tube bundled with the flexible tube and arranged in parallel with the injection nozzle to have an optical system light-receiving portion and left after being wiped. A flexible optical fiber scope for monitoring the fluorescent paint and a flexibility for irradiating the remaining fluorescent paint with ultraviolet light bundled in the flexible tube and the optical fiber scope. And an ultraviolet light irradiation fiber having the same.

[0010]

With the above construction, the flexible tube and the optical fiber scope and the ultraviolet irradiation fiber bundled in the flexible tube are flexibly inserted into the narrow space of the object to be inspected, and the tip end is exposed to the inspection area. I can do it. Here, fluorescent paint is sprayed from the spray nozzle at the tip of the flexible tube and applied to the inspection area. Then, air is jetted from the jet nozzle to wipe off the applied fluorescent paint. In this way, if you wipe after applying the fluorescent paint, the fluorescent paint will remain in the cracks, so it is possible to monitor with the optical fiber scope while irradiating the inspection area with the ultraviolet light with the ultraviolet irradiation fiber. become.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an inspection apparatus 1 which is an embodiment of the present invention.
2 is an enlarged view of the tip portion of the system. The inspection device 1 is provided with a flexible tube 3 having an injection nozzle 2 at its tip. Flexible tube 3
Is a thin tube molded of a flexible material such as resin, and the injection nozzle 2 is molded integrally with this. The spray nozzle 2 is for spraying fluorescent paint or air onto the object to be inspected, and can spray and apply the fluorescent paint onto the object to be inspected, and at the same time the air pressure is applied to the object to be inspected by the wind pressure. The fluorescent paint can be wiped off. The flexible tube 3 transfers fluorescent paint and air to the spray nozzle 2, and an injection source 4 for alternately injecting fluorescent paint and wiping air is connected to the proximal end of the flexible tube 3. ing. In the flexible tube 3, one time of fluorescent paint and one time of wiping air are alternately arranged and accumulated along the flexible tube 3 from the tip end to the base end, Since the inner diameter is sufficiently small, this series will not be broken. By injecting one time of the fluorescent paint or one time of wiping air from the injection source 4, this series is pushed forward and the injection nozzle 2
From this, one time of the fluorescent paint or one time of the wiping air is ejected.

A flexible optical fiber scope 5 is provided for monitoring the fluorescent paint remaining on the flexible tube 3 in a bundle. The optical fiber scope 5 is generally known and is an apparatus for remote monitoring using a flexible optical fiber bundle. An optical system light receiving portion 6 such as an objective lens arranged in parallel with the injection nozzle 2 is provided at the tip of the optical fiber scope 5, and an eyepiece 7 for visual observation is provided at the base end.
A shooting device 8 is provided for enlarging and storing the image. At the base end of the optical fiber scope 5, an automatic focus measurement light source 9 and an automatic focus metering section 10 for adjusting the focus of the photographing device 8 are provided.
The focus of the photographing device 8 can be adjusted by transmitting and receiving the autofocus measuring light through the optical axis 5. These automatic focus measurement light sources 9
And the autofocus photometry unit 10 are generally known,
The provision of these components enables the imaging device 8 to perform autofocus imaging. The photographing device 8 has a TV monitor 11 for displaying the video and a VTR 1 for recording the video.
2. An image processing computer 13 for processing an image is connected. The VTR 12 and the image processing computer 13 can add coordinate information to the image from the photographing device 8 and store it, or can superimpose it on the image under visible light.

Flexible tube 3 and optical fiber scope 5
A flexible ultraviolet light irradiating fiber 14 made of an optical fiber that is bundled with and is capable of transmitting ultraviolet light is provided. The ultraviolet light irradiating fiber 14 is for irradiating the object to be inspected with ultraviolet light and for irradiating the remaining fluorescent paint with ultraviolet light. An ultraviolet light source 15 such as a black light for injecting ultraviolet light into the ultraviolet light irradiating fiber 14 is provided at the base end portion thereof. The tip of the ultraviolet light irradiating fiber 14 is aligned with the tip of the optical fiber scope 5 to form a light emitting surface 16 for ultraviolet light, autofocus measuring light, and the like.

FIG. 3 shows a conceptual diagram of an inspection for metal fatigue of an engine of an aircraft using such an inspection apparatus 1. The engine of the aircraft, which is the object to be inspected, is part 20
Although only the drawing is drawn, the aircraft is not dismantled and is subjected to inspection, so in reality, other members are provided around the engine part 20 so as to cover it and form a narrow inspection space. is doing. The inspection apparatus 1 is a flexible flexible bundle.
Tube 3, optical fiber scope 5, and ultraviolet irradiation fiber 14
Is bent and inserted into a narrow portion sandwiched between the engine portion 20 and other members, and the tip portion is exposed to the narrow portion. Here, since the inspection area 21 is a narrow area, it is in a dark environment or the engine or the like is covered to block external light.

Next, the operation of the embodiment will be described.

As shown in FIG. 3, when the fluorescent paint or the wiping air for one time is injected from the injection source 4 into the inspection device 1 installed so as to face the inspection area 21 of the inspection object, it is pushed out and ejected. The fluorescent paint is sprayed once from the nozzle 2. The sprayed fluorescent paint is applied to the inspection area 21. Then, when one wiping air or one fluorescent paint is injected from the injection source 4, the wiping air is pushed out by this and ejected from the injection nozzle 2 once.
The fluorescent paint applied to the inspection area 21 by the jetting of the wiping air is wiped by the wind pressure, and the fluorescent paint remains in the cracks.

Next, when the ultraviolet light source 15 is turned on to guide the ultraviolet light to the ultraviolet light irradiating fiber 14, the ultraviolet light is emitted from the light emitting surface 16.
Inspection area 2 formed on the surface of the object to be inspected by further irradiation
1 will be reached. The ultraviolet light which hits the metal part in the inspection area 21 is reflected or absorbed. On the other hand, the ultraviolet light that hits the residual fluorescent paint causes a fluorescent effect. That is, the residual fluorescent paint of the crack generates visible light. The background portion of this fluorescent light, that is, the smooth metal surface without cracks is dark because it is shielded from light, so it should be observed from the eyepiece 7 or the photographing device 8 provided at the base end of the optical fiber scope 5. You can In this way, if the position of the fluorescence is confirmed by giving the position information to the image obtained from the photographing device 8, it is possible to detect the presence or absence of the crack and confirm the position. In this way, since the crack can be found and the position thereof can be confirmed, it is possible to inspect the structure having a narrow space and stress concentration without disassembling.

In order to determine the position of the crack, V
The coordinate information can be stored in the TR 12, the image processing computer 13 or the like, or can be superposed on the image under visible light, but as another embodiment of the present invention, a flexible tutor is provided.
Another flexible tube is attached to the tube 3 so that the visible paint is sprayed from the other flexible tube to mark a spot where a crack is found. You can also Marking the cracked spots in this manner facilitates confirmation under visible light. Alternatively, the flexible tube 3 may be exclusively used for the fluorescent paint, and another flexible tube may be provided side by side to eject the air for wiping from the flexible tube. The injection amount and the injection timing of the fluorescent paint and the wiping air may be individually set by supplying the air with a different flexible tube.

Further, as shown in FIG.
Is provided so as to project from the tip of the optical fiber scope 5. This is done in order to prevent the ejected fluorescent paint from bouncing back to the optical system light receiving portion 6 such as the objective lens. The projection length of the injection nozzle 2 may be provided so as to be expandable and contractable so that it can be adjusted appropriately.

[0021]

The present invention exerts the following excellent effects.

(1) Since it has flexibility, it is possible to use fluorescent flaw detection for inspection of a portion such as a bent portion or an inner wall of a conduit which cannot be visually observed directly.

(2) Remote monitoring is possible and automation is promoted.

[Brief description of drawings]

FIG. 1 is a system schematic diagram showing an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the tip portion of the inspection device according to the present invention.

FIG. 3 is a conceptual diagram showing an application example of the present invention.

[Explanation of symbols]

 2 injection nozzle 3 flexible tube 5 optical fiber scope 6 optical system light receiving part 14 ultraviolet light irradiation fiber

Claims (1)

[Claims] 1. A flexible tube for spraying a fluorescent coating on an object to be inspected and for wiping the applied fluorescent coating, which has a spray nozzle at its tip and which transports air after transferring the fluorescent coating. And a flexible optical fiber scope which is bundled in the flexible tube and is provided in parallel with the injection nozzle and has an optical system light receiving portion to monitor the wiped and remaining fluorescent paint. A narrow space characterized by comprising a flexible ultraviolet light irradiating fiber for irradiating the remaining fluorescent coating material with ultraviolet light, which is bundled in these flexible tubes and an optical fiber scope. Inspection device for metal fatigue, etc.