JP2820259B2 - Machinery internal inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an inspection apparatus for inspecting the inside of a structure such as a mechanical device, and more particularly, to inspect, for example, a flaw in an internal structure.
The present invention relates to an internal inspection device in which an optical system such as a lens is inserted into the inside of the structure to enable observation of a target portion from the outside, and a flaw detection inspection device typically used for internal inspection of an aircraft jet engine or the like. It is about.

BACKGROUND OF THE INVENTION The present invention will be described below by taking as an example the internal inspection of an aircraft jet engine in which it is typically used.

Jet engines have compressor blades and turbine blades that rotate at high speed to generate aircraft thrust. Is one of the important things in terms of security, and the inspection is performed at regular intervals and at any time as needed at an appropriate frequency. Such inspections include, in addition to large-scale inspections performed by dismantling the entire engine, inspections inside the device as it is assembled, and in the latter inspection work, the internal structure is directly visually inspected. Since it is not possible to perform the inspection, a method of inserting an elongated tube of a so-called industrial endoscope into the engine and visually confirming the image of the inspection site externally through the optical means of the endoscope is used. Normal.

Such an endoscope optically transmits an image to the rear end of the tube through a relay lens or an optical fiber or the like provided in the tube, and views the image with a viewfinder, or uses a camera having an image pickup tube or a solid-state image sensor. Image processing
This is monitored by an inspection operator on a CRT. The tube uses a hard straight tube made of stainless steel or the like (this is called a rigid endoscope, borescope, or endscope. scope"
) And a type using a flexible tube that can be bent and deformed. In the apparatus to which the present invention is applied, the former borescope (hard endoscope), which is easy to face the examination site, is preferably used, but the present invention is not limited thereto, and a flexible fiberscope may be used. .

FIG. 7 schematically shows an example of the structure of a typical jet engine to be inspected using a borescope. The structure of this engine is such that air compressed by a low-pressure compressor blade 51 is compressed by a high-pressure compressor blade. The compressed air is further compressed by the blades 52, and the compressed air is mixed with fuel in the combustion chamber 53 and burned. The burned high-temperature, high-pressure air rotates the high-pressure turbine blade 54, and further rotates the low-pressure turbine blade 55. The above high pressure turbine blade
54 is coaxially connected with the high-pressure compressor blade 52, and the low-pressure turbine blade 55 is coaxially connected with the low-pressure compressor blade 51, so that the compressor blades 51, 52 are driven by the energy of the exhaust gas rotating the turbine blade. It has a rotating structure. The thrust of the jet engine is obtained by the exhaust gas jet and the airflow by the first stage compressor blades 511 (commonly referred to as "fans").

An example of a flaw detection operation of the jet engine having such a structure, for example, on the high-pressure turbine blade 54 will be described below. FIG. 8 is an enlarged view of a portion surrounded by a circle A in FIG. It is explained as follows. That is, the borescope 1 is fitted from the outside so as to reach the high-pressure turbine blade 54 through the inspection hole 57 provided in the engine casing 56, and the tip thereof is positioned and fixed to face the high-pressure turbine blade 54. For example, a television (TV) camera 58 is connected to the rear end of the borescope 1, and the image of the high-pressure turbine blade 54 is projected on the TV camera 58 through an optical system inside the borescope 1, and connected to the TV camera 58. The image is monitored on a CRT by an image processing system (not shown). Since a large number of high-pressure turbine blades 54 are provided in the rotation circumferential direction, the flaw detection operation is performed while rotating the turbine blades intermittently at a predetermined timing.

The engine is provided with a plurality of inspection holes at necessary locations in order to perform various types of inspection work in addition to the inspection for the high-pressure turbine blade. FIG. Of many inspection holes
The positions of AP1 to AP6 are illustrated.

(Conventional technology) By the way, when performing a flaw detection inspection of a predetermined part inside the engine as described above, this inspection is to monitor an image of the inspection part obtained through an optical medium called a borescope externally. If the engine and the borescope are in an unstable relationship, the obtained image becomes unstable, for example, vibrating. Therefore, it is conceivable to perform inspections by inserting a borescope fixed on the ground side into the engine, but if the engine remains attached to the fuselage, strictly suppress engine vibration. It is difficult to avoid blurring between the groundscope and the fixed borescope on the ground side, which may lead to instability of the detected image and, in severe cases, damage to the borescope. There is also.

It is also conceivable to fix the borescope on the engine side and transmit an image detected by the borescope to a fixed monitor on the ground by optical image projection means. However, there is not enough brightness to perform an optical inspection, and for this reason, a fiber light source is often inserted together with a photographing optical system inside the devices, but it is still difficult to obtain a sufficient amount of light, Therefore, if the optical transmission distance from the photographing optical system to the monitor on the ground side is long, there is a problem that it is difficult to obtain an image with sufficient brightness suitable for inspection due to attenuation.

For this reason, in the flaw detection inspection, it is usual to fix the optical device portion including the borescope to the engine side, and FIG. 10 shows an example of a conventional fixing tool used for this purpose. I have.

The example shown in FIG. 10 is fixed as follows. That is, the catcher 60 is fixed to, for example, the gear box 59 of the engine, and the arm 61 is attached to the catcher 60 with its posture fixed. Next, a platform 62 equipped with a vertical position adjustment mechanism is attached to the tip of the arm 61, and a camera holder 63 equipped with a mechanism for moving back and forth, left and right, and vertical and horizontal angles on the platform 62. The TV camera 58 with the borescope 1 fitted with the tip inserted from an inspection hole provided in the engine casing 56 is fixed to the camera holder 63. Then, the borescope is set to the optimum inspection position by adjusting the position in the front / rear and left / right directions and the angle in the vertical / horizontal angles.

(Problems to be Solved by the Invention) However, in such a type of flaw detection inspection device, a platform (platform) having various kinds of position adjustment and angle adjustment mechanisms as described above is fixed to an engine fixed portion (gear box or the like). It is necessary to be extended from the above, there is a problem that the structure becomes complicated and adjustment is complicated.

Further, there is also a problem that a more complicated platform fixing means is required for an inspection hole in a portion where stable fixing is difficult due to a long extension distance of an arm for fixing the platform.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described drawbacks in an internal inspection device such as a conventional flaw detection inspection device, and to provide an internal inspection device for machinery in which a borescope positioning operation is extremely easy. It is another object of the present invention to provide an internal inspection apparatus having a feature that a structure for positioning is simple and that there is almost no restriction on a mounting place.

(Means for Solving the Problems) Accordingly, the flaw detection inspection for a machine internal inspection apparatus according to the present invention, particularly, typically, an inspection target portion inside an jet engine of an aircraft has been made to achieve such an object. The feature of the device preferably used is that a rigid bar-shaped leg provided with a front end capable of being abuttingly engaged with the outer surface of a wall of a structure such as a mechanical device, and fixed to a rear end of the leg. The photographing device, the at least three wires stretched between the structure and the imaging device in a state where the photographing device is positioned outside the structure via the legs, and A wire tensioning means for tensioning, a photographing optical system inserted into the structure to transmit an image of a target observation region to the photographing device, and a tip of the photographing optical system opposed to the target observation region. Positioning of the shooting optical system And a means for providing the same.

Particularly, typically, for example, an opening inserted in a fixed body of a structure serving as a shielding wall such as an engine casing or the like (hereinafter referred to as an “inspection hole” because it is an opening for inspection) is inserted into the inside, for example. An internal inspection device (for example, a flaw detection inspection device) that allows an image of an internal inspection site of a structure such as a mechanical device to be externally observable through a borescope, wherein the borescope is locked to a peripheral portion of the inspection hole. And a borescope carrier that prevents entry into the fixed body but allows retreat in the outside direction, an imaging device fixed to the rear end of the borescope, and at least a portion around the inspection hole of the fixed body. The configuration includes a wire that is independently stretched between three positions (preferably four points) and the holder, and a wire tensioning unit that tensions the stretched wire.

It is preferable that four wires are stretched between the fixed body and the holder at four points from the viewpoint of workability. The borescope is not limited to this as described above. For example, the borescope may be one in which an optical fiber is internally penetrated inside a hard cylinder, and in short, a leg that holds the holder together with the wire in a fixed position. What is necessary is just to combine the hard rod-shaped or cylindrical member which plays the role of and the optical means of image projection. In the above, when the leg is fixed to the center of the photographing device, and the photographing device is tensioned and suspended by four wires connected to the upper, lower, left, and right peripheral edges, the pair arranged symmetrically around the leg is Since the wire to be formed functions to suppress tilting to the opposite side of the imaging device,
There is an advantage that the posture of the photographing device is stabilized even if there is vibration or the like.

A mechanism for extending a plurality of wire members from a holder to a casing of an engine or the like in an internal inspection device of the present invention, for example, a flaw detection inspection device, typically, for example, when an inspection target is a jet engine of an aircraft Can be easily configured by providing a hook at the tip of the wire, unwinding the wire having the hook at the tip from a wire reel mounted on a holder, and hooking the hook on a structural frame or the like of the engine. The wire tensioning means can be constituted by, for example, a means for locking the unwinding of the wire from the wire reel, and further, a mechanism for retracting the borescope from the engine casing to further tension the tensioned wire. May be provided. Thus, the borescope and the holder fixed to the rear end can be stably attached to a fixed body such as an engine by a wire tension by a plurality of strained wires and a borescope carrier that restrains the movement of the borescope in one direction. Supported.

The wire tensioning means having the function of retracting the borescope from the shielding wall of the engine casing or the like can be configured as follows, for example, if one example thereof is specifically described. That is, a bolt member and a nut member that are screwed together and a pair of sockets rotatably fitted to one of the bolt member and the nut member are used, for example, rotatably fitted to the bolt member among them. The fixed socket is locked to the peripheral edge of the opening of the fixed body, and the nut member is fixed to the borescope. With this configuration, by rotating the bolt member, the nut member relatively retreats from the bolt member in a non-rotating state, and the tension of the stretched wire is given. In this case, the socket constitutes a borescope carrier.

As the borescope in the present invention, a known one can be used, and a TV camera can be generally used as an optical monitoring means to be attached to the rear end of the borescope. For example, the present invention is not limited to this, and the optical fiber cable may be used to connect to an image processing apparatus provided elsewhere.

(Operation) With the above configuration, the present invention can easily fix a photographing device such as a television camera and a photographing optical system when optically observing the internal structure of machinery from the outside.

(Example) Hereinafter, an example in which the internal inspection device of the present invention is a flaw detection inspection device that inspects a flaw of a member having an internal structure of machinery will be described with reference to the drawings.

FIG. 1 shows a borescope 1 having a built-in photographic optical system as a hard leg, and a TV camera attached to the rear end thereof.
An embodiment in which a TV camera and a holder on which a wire reel or the like which is a wire stretching means for fixing and fixing a borescope is mounted on an exterior is shown.

In the above embodiment, reference numeral 1 denotes a borescope, in which an optical element such as a relay lens (not shown) is incorporated in a hard tube made of stainless steel or the like, and an object on which a front objective lens faces is located on a rear end side. Eyepieces (none shown)
In this example, a pan-viewing type having a viewing angle with respect to the front of the tip of the borescope may be used, but in this example, as shown in FIG. On the other hand, a type having a viewing angle is used.

Reference numeral 2 denotes a wire tensioning means which is mounted at an intermediate position of the axis of the borescope 1 and also serves as a borescope carrier, and its detailed structure is shown in FIG.

Reference numeral 3 denotes a TV camera attached to the rear end of the borescope 1 and a camera holder fixed externally to the TV camera. The outline and detailed structure of the TV camera are shown in FIGS. 2 and 4 to 6.

First, the wire tensioning means 2 serving as the borescope carrier of the present embodiment will be specifically described below.

The wire tensioning means includes a sleeve 21 inserted into the borescope 1, a split metal fitting 22 incorporated in a cylinder of the sleeve 21, and a female screw portion at the rear end of the sleeve.
By tightening by screwing on the 211, the split metal fitting 22 is pressed against the outer periphery of the borescope 1, thereby tightening the sleeve 21 and the borescope 1 so as to restrain the relative movement in the axial direction. A nut member that is screwed to the nut 23 and the distal male screw portion 212 of the sleeve 21 and that is rotatably provided in such a manner that the span of both can be extended and shortened in the axial direction by the relative screwing rotation. 24, and consists of. The nut member 24 of the present embodiment is coupled to a head socket 241 which is engaged and locked on the periphery of the inspection hole 57 of the engine casing 56, and is rotatable with respect to the head socket 241 and is immovable in the axial direction. The thread tension nut 242 includes a male thread portion 243 that is screwed to the distal female thread portion 212 of the sleeve 21. A wire tensioning knob 244 is used to manually rotate the wire tensioning nut 242.

The operation of using the wire tensioning means 2 also serving as a borescope carrier will be described. First, the entirety is inserted into the borescorp 1 with the tightening nut 23 being loosened with respect to the sleeve 21, and the sleeve 21 is inserted at a predetermined position. Tightening nut
By tightening 23, the sleeve 21 is fixed to the borescope 1.

Next, the tip of the borescope 1 is connected to the inspection hole 57 of the casing 56.
From the head socket 24
1 is locked on the periphery of the inspection hole 57. Thus, the approximate position of the borescope 1 with respect to the casing 56 is determined. At this time, the tightening nut 23 may be loosened to adjust the axial position of the borescope 1.

When the wire tensioning knob 244 is rotated, the wire tensioning knob 244 rotates with respect to the head socket 241 and the sleeve 21 (the head socket 241 and the sleeve 21).
Does not rotate), and the sleeve 21 moves from the head socket 241 rightward in FIG. 3A (rightward in FIG. 1) by an amount corresponding to the amount of rotation. This movement is for tensioning a wire stretched between the camera holder and the casing 56, as will be described later. This point will be described later.

 Next, the camera holder 3 will be described.

As shown in FIGS. 2 and 4, the camera holder 3 is provided so as to straddle a TV camera 58 (581 is a camera head) to which the rear end of the borescope 1 is fixedly connected. It is fixed to the TV camera 58 by mounting bolts (not shown) at mounting holes 311, 311,... Provided in the top plate portion 31. The two side legs 32, 32 of the camera holder 3 have a symmetrical structure, and two pairs of wire reels 34, 34 capable of unwinding the tension wires 33, 33, respectively, are mounted on these legs. Thus, four tension wires can be fed from the camera holder 3 (see FIG. 2).

The tension wire 33 is wound and can be unwound as required. The wire reel 34 has a spring (not shown) that applies a rotational force in the wire winding direction and a wire 33. Can be drawn out to an appropriate length. 36 is an unwinding wire guide tube,
Reference numeral 37 denotes a stopper which forms a wire winding limit. A hook 35 shown in FIG. 6 is connected to the distal end of the wire 33, and a shock absorbing rubber 38 that engages with the stopper 37 as a winding stopper is fixed near the hook 35.

The wire reel 34 includes a wire winding section 341 and a gear section 342 adjacent thereto.
In this case, the rotation of the reel can be locked by engaging with a key 343 (in this example, two with the gear teeth shifted by one pitch) for locking the rotation of the gear (see FIG. 5). . The key 343 is urged in the engagement direction by a lock spring 344, and the lock can be released by the swing operation of a lock release lever 346 by the operation of an electromagnetic switch 345. Reference numeral 347 denotes a slack-preventing leaf spring for preventing the wire 33 wound around the wire reel 34 from being loosened.

Reference numeral 348 denotes a lock release switch for turning the electromagnetic switch 345 on and off. When the electromagnetic switch 345 is turned on, the electromagnetic switch 345 is turned on to release the rotation lock of the wire reel 34 by the key 343, thereby unwinding the wire 33. At the time of resetting, the electromagnetic switch 345 is turned off, and the key 343 is used.
Operates to lock the rotation of.

An example of an operation of fixing the flaw detection apparatus having the above configuration to the engine casing will be described first.
23 is loosened with respect to the sleeve 21, and the screw between the nut member 242 for wire tension and the sleeve 21 is screwed up to the maximum screw-in position, so that relative movement between the sleeve 21 and the borescope 1 is performed. The operator holds the camera holder with his / her hand, and the borescope 1 is fitted into the inspection hole 57 of the casing 56 of the jet engine. Then, the head socket 241 is engaged with the periphery of the inspection hole 57 at a position where the objective lens is substantially opposed to a predetermined inspection target portion (the turbine blade 54 in the example of FIG. 8), The fastening nut 23 is fastened to the sleeve 21. As a result, further entry of the borescope 1 into the engine casing is restricted.

Next, the lock release switch 348 of the camera holder 3 is set to release the rotation lock of the wire reel 34. Then, the wires 33 from the four wire reels 34 of the camera holder 3
Are sequentially unwound, and the hook 35 at the tip thereof is hooked to an appropriate portion of the engine. The stretching of these four wires 33
It is preferable that the hook 35 be hooked so that the posture of the camera 58 is suitable for stabilizing and suspending and supporting the camera 58, for example, a substantially rectangular vertex position. When the wire 33 is stretched by hooking the tip hook 35 as described above, the wire reel 34 is urged by the spring force in the wire rewinding direction, so that the wire reel 34 is stretched without slack.

In this state, the lock release switch 348 is reset to lock the rotation of the wire reel 34 by the key 343.

Next, by rotating the wire tensioning knob 244 of the wire tensioning means 2 also serving as the borescope carrier, the sleeve 21 is retracted toward the outside of the casing 56 (the sleeve 21 and the head socket 241 do not rotate). The borescope 1 integrated with the shaft 21 so as to be immovable in the axial direction is slightly retracted, so that the four wires
33 is tensioned, and the support of the camera holder by the four wires 33 becomes stable. Therefore, thereafter, stable support of the borescope 1 to the engine casing 56 is secured without artificially supporting the camera holder.

The above operation is a simple operation that can be performed only by tightening the nut and hooking the hook to an appropriate position. The operation is simpler than the conventional operation using the device described in FIG. In addition, there is an extremely excellent effect in terms of simplicity of the device structure used.

The removal of the device can be easily released by releasing (unlocking) the electromagnetic switch 345, and the next attachment to another inspection hole 57 can be performed immediately.

Note that the wire tensioning means in this example can be omitted. That is, when the wire is stretched while the camera holder is supported by hand, the wire is tensioned to a certain degree by the rewinding force applied to the wire reel 34, and this wire is locked to support the camera holder. Even if you release
The displacement of the camera holder due to its own weight can be suppressed within the range of the attitude change of the TV camera 58 to such an extent that it does not hinder the actual work due to the Young's modulus of the wire, the rewinding force applied to the wire reel 34, and the like. Because you can.

FIG. 11 is for explaining another embodiment of the present invention. The feature of this embodiment is that the TV camera 58 and the leg 70 of the integrated camera holder are mounted on the wall near the opening of the casing 56 of the apparatus. A fixed pad 71 is abutted and engaged with the tip, and an optical fiber cable 73 is used as a photographing optical system. This rear end is connected to the TV camera 58, and the tip of the optical fiber cable 73 is connected to the opening of the casing 56. That is, the known fiber fitting tube 72 attached to 57 is positioned at a predetermined position inside the engine. Other configurations are substantially the same as those of the above-described embodiment, and a description thereof will be omitted.

According to this example, since the legs 70 are only used for positioning and fixing the TV camera 58, there is an advantage that the shape and material can be selected without optical consideration, and the optical fiber cable 73 is too long. Since a predetermined image can be transmitted to the TV camera 58 without using a scale, the brightness of the photographed image portion is generally low, and therefore, it is useful as this type of inspection apparatus in which attenuation often occurs when projecting an image.

In this example, similarly to the above-described embodiment, the fixed pad
A mechanism that allows the leg 70 to be non-rotatably screwed out from the direction 71 toward the TV camera 58 may be provided.For example, the return spring of the reel that is unwound when the wire is stretched is set to have an appropriate strength. By combining with the wire unwinding locking means, the screwing-out mechanism can be omitted. That is, in this example, since the optical fiber cable is used, the attitude of the TV camera 58 does not basically matter.

It is needless to say that the present invention is not limited to the above-described embodiment, and it is of course possible to use mechanical devices other than the engine of the aircraft and to use the devices for purposes other than flaw detection.

(Effect of the Invention) As described above, the internal inspection device for machinery of the present invention
There is an effect that the work of positioning and fixing the optical system and the photographing device, which are the mediating means of image transmission, can be performed extremely easily.

Further, for example, the mechanism for positioning the borescope has a very simple structure, and furthermore, wires are used for the positioning and fixing, and there are almost no restrictions on the mounting place, and in particular, the jet engine of the aircraft described in the above-described embodiment. In addition to being suitably used for flaw detection operation inspection, the present invention has an effect that high versatility can be obtained such that it can be applied to various objects.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an outline of an assembling structure when the present invention is applied to a flaw detection inspection apparatus for an aircraft jet engine, and FIG. 2 is a perspective view showing an outline of a structure of a holder externally fixed to a TV camera. FIG. FIG. 3 (a),
(B), (c) is a diagram showing the configuration of the wire tensioning means attached to the borescope, (a) is a side view of the lower half section, and (b) is a diagram ( (a) is a left end view, and (c) is a cross-sectional view taken along line AA of (a). 4 (a), 4 (b) and 4 (c) are views showing details of the structure of the camera holder, wherein FIG. 4 (a) is a side view of the camera holder, FIG. 4 (b) is a plan view, and FIG. (c) is a front view. 5 (a) and 5 (b) are views for explaining the configuration of a lock means for locking the unwinding of the wire, where FIG. 5 (a) is a side view and FIG. 5 (b) is a plan view. FIG. 6 is a view showing a hook at the tip of the wire. FIG. 7 is a view schematically showing an example of the structure of a jet engine of an aircraft to which the embodiment of FIG. 1 is applied.
The figure is an enlarged view of a circle A in FIG. FIG. 9 is a view showing the arrangement of a part of the inspection hole of the jet engine, and FIG. 10 is a view schematically showing the structure of a conventional apparatus for fixing a borescope. FIG. 11 is a diagram showing an outline of a mounting configuration of a flaw detection apparatus to a jet engine for explaining another embodiment of the present invention. 1: Borescope 2: Wire tension means also serving as a borescope carrier 3: Camera holder 21: Sleeve, 211: Rear end female thread 212: Tip female thread 22: Split metal fittings, 23: Tightening nut 24: Nut member, 241: Head socket 242: Nut for wire tension 243: Male thread 244: Knob for wire tension 31: Top plate, 32: Leg 33: Wire, 34: Take-up reel 341: Wire take-up, 342: Gear Part 343: Key, 344: Lock spring 345: Electromagnetic switch, 346: Lock release lever 347: Locking plate spring 348: Lock release switch 35: Hook, 36: Guide tube 37: Stopper 38: Shock absorbing rubber 51: Low pressure compressor Blade 52: High pressure compressor blade 53: Combustion chamber 54: Low pressure turbine blade 55: High pressure turbine blade 56: Casing, 57: Inspection hole 58: TV camera, 59: Gear box 60: Catcher, 61: Arm 62: Platform, 63: Camera holder 70: legs, 71: anchor pad 72: Fiber fitted intubation 73: optical fiber cable

Continuation of front page (58) Fields investigated (Int.Cl. ⁶ , DB name) G01N 21/84 G01M 15/00 G02B 23/24

Claims (7)

(57) [Claims] 1. A hard bar-shaped leg provided with a front end capable of being abutted against and engaged with an outer surface of a wall of a structure such as a mechanical device, and a photographing device fixed to a rear end of the leg. At least 3 which is stretched between the structure and the photographing device in a state where the photographing device is separately positioned outside the structure via the legs.
A book wire, wire tensioning means for tensioning these tensioning wires, a photographing optical system fitted to the inside of the structure and transmitting an image of a target observation region to the photographing device, and a photographing optical system. An internal inspection apparatus for machinery, comprising: a positioning unit for a photographing optical system that causes a front end of a system to face the target part. 2. The apparatus according to claim 1, wherein the leg is a cylindrical body, a tip is inserted into a structure, and the photographing optical system is provided inside the cylindrical body. Inspection equipment for machinery. 3. The internal inspection apparatus for machinery according to claim 2, wherein the cylindrical body containing the photographing optical system is a borescope. 4. An internal inspection apparatus for machinery according to claim 1, wherein said photographing apparatus is a television camera having a fixed holder externally mounted. 5. The machine internal inspection apparatus according to claim 1, wherein the inspection object is inside the jet engine of the aircraft. 6. A bolt member and a nut member which are screwed to each other, and a pair of sockets rotatably fitted to one of the bolt members and the nut members. And the other one of the bolt member and the nut member is fixed to the hard cylinder, and the rotation of the one member allows the other member to relatively screw out and retreat, so that the hard cylinder carrier The internal inspection device for machinery according to any one of claims 1 to 4, wherein the device comprises a wire tensioning means. 7. The internal inspection apparatus according to claim 1, wherein the number of the wires is four extending from the upper, lower, left, and right peripheral positions of the photographing apparatus.