JPH07113749A - Turbine blade inspection system - Google Patents

Abstract

PURPOSE:To provide a turbine blade inspection system by which the still picture of a turbine blade can be obtained in a short time without requiring turning tool control or special ancillary tools and materials such as a stroboscope light source device. CONSTITUTION:A turbine blade inspection system 1 is composed of an electronic endoscope 2 having a CCD 21, a light source device 3 to supply illumination light to an illumination optical system of the electronic endoscope 2 and a processor 4 to process various signals. An image pickup element driving device 31 to control image pickup time of the CCD 21, an image signal processor 32 to process an electric signal transmitted from the CCD 21 into an image signal, an image display device 33 which can superimpose an optional diagram or character or the like on each other, a CPU 34 to control the whole system such as the image pickup element driving timing or taking in of an image and a magnetic disk 35 to record an object image whose image is picked up, are arranged in the processor 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine blade inspection system for detecting damage such as cracks generated in turbine blades of jet engines for aircraft and engines for generators.

[0002]

2. Description of the Related Art Conventionally, for example, when inspecting a turbine blade inside a jet engine, a tip of an electronic endoscope using a fiberscope or CCD using an optical fiber is inserted into the jet engine, The inspection was performed while moving the turbine blades one by one so that they were within the field of view of the endoscope.

Japanese Patent Publication No. 62-35614 has a turning tool for rotating a turbine rotor having turbine blades and a turning tool control unit for controlling the turning of the turning tool. Jet that can inspect the turbine blade one by one by positioning and fixing the mirror to the turbine blade in advance, controlling the turning tool with the turning tool control unit, shifting the turbine rotor one step at a time. An engine flaw detection system is shown.

Further, in Japanese Patent Application Laid-Open No. 2-62524, an optical fiber for irradiating a strobe light from a strobe capable of high-speed light emission is arranged on a rotating body, and a signal indicating a photographing position of the rotating rotating body and a shutter signal are provided. It shows a rotating body photographing device that shoots a still image of a desired part while the movement of the rotating body is stopped while the strobe fires when it is input at the same time and it is exposed to the photographing machine only during this light emission time. There is.

[0005]

However, it is a very time-consuming work to carry out the inspection by moving the turbine blades one by one so that they are within the field of view of the endoscope. Further, in the jet engine flaw detection system disclosed in Japanese Patent Publication No. 62-35614, a turbine rotor rotated using a turning tool to obtain an image of a turbine blade is controlled by a turning tool control unit to obtain a desired rotation angle. At that time, the rotation of the turbine rotor was stopped to obtain the desired image, but the work to obtain the image by stopping the rotation of the turbine rotor once and once is troublesome, it takes time, and every time the inspection is performed, the turning tool control is performed. I had to prepare a unit.

Next, in the rotating body photographing apparatus disclosed in Japanese Patent Laid-Open No. 2-62524, since it is possible to perform photographing in a rotated state, the rotation of the rotor is stopped once and then once. Although the troublesome work of obtaining an image has disappeared, it was necessary to provide a rotating pulse detector, a switching circuit, an accessory device such as a photographing strobe capable of high-speed light emission, and a circuit for synchronization.

The present invention has been made in view of the above problems, and does not require auxiliary equipment such as a turning tool control unit or a high-speed light emitting flash light source device or a special circuit, and a still image of a turbine blade can be obtained in a short time. It is an object to provide an obtained turbine blade inspection system.

[0008]

SUMMARY OF THE INVENTION A turbine blade inspection system of the present invention comprises a turning tool for rotating a turbine rotor having a plurality of turbine blades, and a turbine blade for observing damage caused to the turbine blade. An electronic endoscope that is positioned and fixed so as to enter the field of view, a light source device that illuminates a turbine blade via an illumination optical system provided in this endoscope, and an endoscopic image of the electronic endoscope is recorded. A plurality of turbine blades rotating by the turning tool so as to be brought into the field of view of the endoscope one by one at a desired timing, and each time the turbine blade enters the field of view of the endoscope. The endoscopic images picked up in step 1 are sequentially recorded in the recording means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described below with reference to the drawings.

1 to 4 relate to an embodiment of the present invention. FIG. 1 is a block diagram showing a schematic configuration of a turbine blade inspection system, and FIG. 2 is a tip portion of an electronic endoscope in a gap between adjacent guide vanes. FIG. 3 is a diagram showing a state in which is inserted, FIG. 3 is an explanatory view showing an optimum composition for inspecting a turbine blade displayed on a monitor through an imaging means, and FIG. 4 is a chart showing a flow of inspection of the turbine blade inspection system.

As shown in FIG. 1, a turbine blade inspection system 1 includes an image pickup device (hereinafter referred to as CCD) for inspecting a turbine blade of a jet engine body 70, which will be described later.
An electronic endoscope 2 including: a light source device 3 such as a high-intensity xenon lamp for supplying illumination light for illuminating a subject through an illumination optical system of the electronic endoscope 2, and a processing device for performing various signal processings. 4 and.

The electronic endoscope 2 is composed of a distal end portion 21 having a built-in CCD, an elongated insertion portion 22 which is inserted into the jet engine body, and an operation portion 23 which also serves as a grip portion on the near side. There is.

The processing device 4 is an image pickup device driving device 3 for controlling the image pickup time (shutter speed) of the CCD 21.
1, a video signal processing device 32 for photoelectrically converting a subject image formed on the CCD 21 to process the transmitted electric signal into a video signal, and an image memory capable of superimposing arbitrary figures and character information. The image display device 33 and the CPU 3 that controls the entire system such as the timing of shutter speed and image capture, information recording, and information storage
4 and a magnetic disk device 3 for recording the captured subject image
It is composed of 5, etc. An image obtained by superimposing various kinds of data on the video signal processed by the video signal processing device 32 is displayed on the screen of the monitor 5.

A reference numeral 6 is a keyboard, and by inputting various commands from this keyboard, the CP
A command signal is output to each device via U34. Further, reference numeral 71 is a turning tool that generates a driving force for rotating the turbine rotor in the engine body, and the driving force is transmitted to the turbine rotor via the gear box 72. Reference numeral 73 is an access port, through which the electronic endoscope 2 is inserted into the main body of the jet engine.

The procedure up to the inspection of the turbine blade inspection system 1 configured as described above will be described. As is well known, high temperature and high pressure air for injecting propulsive force into an aircraft is jetted to the turbine blades, which causes a large thermal shock. Therefore, as shown in FIG.
It is necessary to insert the insertion portion 22 of the electronic endoscope 2 into 0 and periodically inspect the turbine blade 75.

When inspecting the turbine blade 75, first, the insertion portion 22 of the electronic endoscope 2 is accessed from the access port 73.
Is inserted through the gap between the turbine nozzle guide vanes 74 that are stationary with the engine case (not shown) incorporated. Then, as shown in FIG. 3, the distal end portion 21 is provided opposite to the turbine blade 75, and the turbine blade 75 is provided at the center of the field of view of the endoscope so that it is easy to inspect for damage such as cracks.
Is adjusted so that the insertion portion 22 is fixed.

A composition suitable for inspecting the turbine blade 75 will be described with reference to FIG. This turbine rotor has, for example, a total of 100 turbine blades 75, 75, 75. ． ． Is provided. And
An electronic endoscopic image of the turbine rotor 75 to which numbers A1, A2, ... A100 are explicitly attached as shown in the drawing is output to the monitor 5. At this time, the image is affected by the distortion aberration. In the case of a commonly used electronic endoscope, the amount of distortion due to the distortion aberration increases as it spreads from the center of the screen to the outer peripheral side. Therefore, the composition in which the object to be inspected is displayed in the central portion of the screen like the turbine blade 75 (Al) in the figure is the least affected by the distortion aberration, and is suitable for observation by the electronic endoscope 2.

Next, the turning tool 71 is driven to rotate the turbine rotor (start in FIG. 4). The rotation speed of the turbine rotor at this time is a predetermined speed, and the turbine blades 75, 75, 7
5. ． ． Is the speed at which the electronic endoscope 2 comes into the field of view while shifting one by one.

Next, the shutter speed of the CCD incorporated in the electronic endoscope 2 to which the insertion portion 22 is fixed is converted. Enter a command to convert the shutter speed from the keyboard 6 and
The shutter speed of the CCD for 60 sec is changed to 1/1000 sec, which is suitable for still image capturing. Then,
The image of the subject of the turbine blade 75, which is formed into a CCD for 1/1000 sec and converted into an electric signal, is subjected to image signal processing by the image signal processing device 32, and is temporarily stored in an image memory incorporated in the image display device 33. It is read from the image memory and a still image of the turbine blade 75 is displayed on the monitor screen. At this time, the turbine blade 75
When the endoscopic image of is shifted from the center part of the screen, a command for converting the timing of opening the shutter is input from the keyboard 6, and the endoscopic image of the turbine blade 75 is adjusted to be displayed in the center part of the screen. Then, the inspection preparation is completed.

The flow of inspection of the turbine blade inspection system 1 which has completed the inspection preparation as described above will be described with reference to FIG. First, as shown in step S1, the counter is reset, the process proceeds to step S2, and an image recording command is input from the keyboard 6. Then, the CPU 34
In response to the image recording command, the counter increments the counter as shown in step S3, and as shown in step S4, the number of turbine blades 75 arranged in the turbine rotor as the inspection object exceeds the total number. Whether or not it is determined. Then, if the number of turbine blades 75 is within the total number, endoscopic images are sequentially captured and recorded on the magnetic disk 35 via the video signal processing device 32 and the image display device 33.

At this time, each endoscopic image in which various data such as the turbine blade count number, date, time, turbine rotor type, etc. is taken in by the superimposing device incorporated in the image display device 33. Superimpose on. Here, the count number is C
The number of images recorded on the magnetic disk device 35 under the control of the PU 7 is shown. Then, when the counted number becomes equal to the total number, the image recording (inspection) is ended. That is, when recording images of the turbine blades A1 to A100, the counter is incremented by 1 each time an image recording command is input, and the turbine blade A
1 is counter 1 and turbine blade A2 is counter 2
become. After that, if you sequentially record up to A100, the counter 1
It is 00, which means that the recording of all turbine blades has been completed.

As described above, the plurality of turbine blades are moved at a preset speed using the turning tool, and the shutter speed of the CCD provided in the electronic endoscope is set to a speed suitable for obtaining a still image. By converting to, it is possible to obtain a still image of the turbine blade in a short time without requiring special equipment.

In the present embodiment, an example in which an electronic endoscope is used as the image pickup means has been described, but a fiberscope can also be used. In this case, if an external video camera equipped with a CCD is attached to the fiberscope, the same effect as the above embodiment can be obtained.

Further, in the present embodiment, the image capturing signal is output from the CPU by inputting the image recording command from the keyboard, but it is most suitable for the turbine blade inspection instead of the image recording command input. A known image processing method may be used to determine whether or not an image composition has been obtained, and an image recording command may be output when an appropriate image composition is obtained.

Further, although the present embodiment has been described with respect to a jet engine for an aircraft, it is needless to say that the same inspection can be performed as long as it has various turbine blades such as a generator engine.

By the way, the cone mirror used in the in-pipe all-around inspection device is weak in strength when the mirror portion is exposed and may be scratched when attempting to clean the attached dust or the like. Further, the cone mirror having a notched tip surface had a complicated shape and was effective. Therefore, by configuring the mirror as follows, it is inexpensive and
It is possible to provide a cone mirror in which dirt is prevented.

As shown in FIGS. 5 to 9, a cylindrical transparent member having a built-in cone mirror is connected to the tip of the observation optical system.

Cone mirror 81a shown in FIGS. 5 and 6.
Is disposed inside the transparent cylindrical member 82,
Dust is less likely to adhere, and the manufacturing cost can be reduced. Reference numeral 84 is a light guide bundle.

The cone mirror 81a shown in FIG. 6 has a structure in which the light guide bundle 84 slides back and forth with respect to the observation optical system 83. Therefore, it is possible to adjust the light guide position to an optimum position depending on the tube diameter.

In FIGS. 7 and 8, a cone mirror is arranged on the tip surface of the cylindrical transparent member 85. At this time, the cone mirror 81b shown in FIG. 7 improves the light distribution at the near point by using the thick portion as the reflecting surface, and the cone mirror 81b shown in FIG. 8 uses the inner peripheral surface of the cylindrical transparent member 85 as the reflecting surface 85a. By doing so, the overall light distribution is improved.

The cone mirror 81c shown in FIG. 9 is formed by integral molding and is inexpensive.

[0032]

As described above, the turbine blade inspection system of the present invention does not require any special accessory equipment such as a turning tool control and a strobe light source device.
It is possible to obtain a still image of the turbine blade in a short time.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention, and FIG. 1 is a block diagram showing a schematic configuration of a turbine blade inspection system.

FIG. 2 is a diagram showing a state in which a tip portion of an electronic endoscope is inserted into a gap between adjacent guide vanes.

FIG. 3 is an explanatory view showing an optimal composition for inspecting a turbine blade displayed on a monitor through an imaging means.

FIG. 4 is a chart showing a flow of inspection of a turbine blade inspection system.

FIG. 5 is a diagram showing a configuration example of a cone mirror.

FIG. 6 is a diagram showing another configuration of the cone mirror.

FIG. 7 is a diagram showing another configuration of the cone mirror.

FIG. 8 is a diagram showing another configuration of the cone mirror.

FIG. 9 is a diagram showing another configuration of the cone mirror.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Turbine blade inspection system 2 ... Electronic endoscope 3 ... Light source device 31 ... Imaging device drive device 32 ... Video signal processing device 71 ... Turning tool

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[Procedure amendment]

[Submission date] December 9, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

By the way, the cone mirror used in the in-pipe all-around inspection device is weak in strength when the mirror portion is exposed and may be scratched when attempting to clean the attached dust or the like. Further, the cone mirror having a notched tip surface has a complicated shape and is expensive . Therefore, by configuring the mirror as follows, it is inexpensive and
It is possible to provide a cone mirror in which dirt is prevented.

Claims (1)

[Claims] 1. A turning tool for rotating a turbine rotor having a plurality of turbine blades; an electronic endoscope positioned and fixed so that the turbine blades are in view for observing damage caused to the turbine blades; A light source device that illuminates a turbine blade via an illumination optical system provided in this endoscope, and a recording unit that records an endoscopic image of the electronic endoscope, are provided. The turbine blades are shifted one by one so as to enter the field of view of the endoscope at a desired timing, and endoscopic images taken at each timing when the turbine blade enters the field of view of the endoscope are sequentially recorded in the recording means. A turbine blade inspection system characterized in that