JP6800447B2 - Rolling tapping mechanism - Google Patents

Description

The present invention relates to, for example, a rolling tapping mechanism used for piping inspection in a chemical plant.

In chemical plants, many pipes are laid in the facility, and if a leak accident should occur, it may cause a serious situation such as fire or generation of harmful gas.
In particular, corrosion inside the pipe and corrosion on the outer surface of the pipe under the heat insulating material (CUI) cannot be confirmed by visual inspection.
For this reason, conventionally, inspections by the AE method (acoustic emission) and inspections performed by inserting an inspection unit such as a CCD camera unit or an eddy current flaw detection unit into a pipe have been adopted.

Patent Document 1 describes a piping inspection device in which a CCD camera unit and an eddy current flaw detection unit are mounted on a connected vehicle for inspection.
Further, Patent Document 2 describes a piping inspection mechanism in which cables having different rigidity are connected in multiple stages to a rotary drive unit connected to an inspection device head.

Japanese Unexamined Patent Publication No. 2005-241474 JP-A-11-125385

However, in the piping inspection by the AE method, not only the equipment is expensive, but also the installation is complicated, and the inspection accuracy may be deteriorated due to the influence of electromagnetic noise.
Further, the piping inspection device disclosed in Patent Documents 2 and 3 also has a complicated mechanism, and particularly in a bent thin tube or the like, the inside of the pipe cannot be moved smoothly, and the inspection device is locked in a place where the bending angle is large. There was a problem that it became impossible to take it out.

Therefore, an object of the present invention is to enable smooth passage by flexibly bending according to the shape of the inside of the pipe, and to generate a tapping sound by a roller that rotates as the pipe moves in the pipe. By acoustic analysis, it is possible to reduce the size and weight and cost, and even for thin pipes with bent parts, it is possible to accurately inspect and diagnose the progress of corrosion over the entire length of the pipe. To do.

In order to solve this problem, the rolling sound tapping mechanism of the present invention has an elastic support provided with a central shaft member towed by a tow cable and an arm attached to the central shaft member and extending in the radial direction from the central shaft member. It consists of a portion and a plurality of tapping rollers rotatably supported by an arm, and when inserted into the pipe, the arm of the elastic support portion uniformly suppresses the tapping roller against the inner wall of the pipe in the circumferential direction. , Centering is performed so that the central axis of the central axis member coincides with the central axis of the pipe, and the rotation axis of the tapping roller is tilted with respect to the central axis of the central axis member, so that the central axis member is pulled. The tapping sound roller was rotated, and the tapping sound ball provided on the outer surface of the roller was used to strike the inner wall of the pipe.

According to the present invention, even in a bent pipe portion, the arm of the elastic support portion elastically deforms to follow the inner wall of the pipe while reliably rotating the tapping roller, which is a low-cost and small-diameter bent pipe. However, it is possible to accurately inspect and diagnose the progress of corrosion over the entire length of the pipeline.

FIG. 1 is a diagram showing an overall structure of an embodiment. FIG. 2 is a diagram showing a mode in which both ends of the tapping roller 5 in the rotation axis direction are partially brought into contact with the inner wall of the pipe. FIG. 3 is a diagram showing the behavior of the elastic support portion 3 when passing through the right-angled pipe. FIG. 4 is a diagram showing the behavior when the central shaft member 1 is made bendable. FIG. 5 is a system diagram of a piping inspection device using this embodiment. FIG. 6 is a diagram showing an example in which a centering ball and a pop noise reduction cage are arranged before and after the rolling type tapping mechanism. FIG. 7 is a diagram showing a rolling type tapping mechanism manufactured according to the inner diameter of the pipe. FIG. 8 is a diagram showing the results of principal component analysis of tapping sound by the rolling tapping sound mechanism. FIG. 9 is a diagram showing the results of linear discriminant analysis of tapping sound by the rolling tapping sound mechanism.

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which a central shaft member 1 towed by a tow cable 2 and an elastic support mounted between the front end and the rear end of the central shaft member 1 when viewed from the towing direction. It is composed of portions 3 and 4 and a striking sound roller 5 rotatably supported by elastic support portions 3 and 4.

In this embodiment, the elastic support portion 3 is a boss portion 3a connected to the front end of the central shaft member 1, and two base ends extending from the boss portion 3a in a direction orthogonal to the axial direction of the central shaft member 1. It is composed of portions 3b and 3c, and two arms 3d and 3e that are curved in a plane orthogonal to the proximal end portions 3b and 3c at the end portions of the proximal end portions 3b and 3c.
The hitting sound roller 5 is rotatably supported around the rotating shaft 5a via a ball bearing or the like, and both ends of the rotating shaft 5a are attached between the opposite tips of the arms 3d and 3e. ..
As a result, the elastic support portion 3 supports the two tapping sound rollers 5 so as to face each other.

The elastic support portion 4 has the same structure as the elastic support portion 3, and has two base ends extending in a direction orthogonal to the axial direction of the central shaft member 1 from the boss portion 4a connected to the rear end of the central shaft member 1. The portions 4b and 4c (not shown) are arranged so as to be orthogonal to the base end portions 3b and 3c of the elastic support portion 3 so as to be offset by 90 degrees with respect to the central shaft member 1.
Therefore, the two hitting sound rollers 5 supported by the elastic support portion 3 and the two hitting sound rollers 5 supported by the elastic support portion 4 face each other, and a total of four hitting sound rollers 5 around the central shaft member 1 at 90-degree intervals. It will be placed. However, in this embodiment, the striking roller rotating shaft 5a on the elastic support portion 3 side is arranged axially forward with respect to the striking roller rotating shaft 5a on the elastic support portion 4 side, and passes through the right-angled pipe. Even in such a case, one of them is in contact with the inner wall of the pipe. Further, each tapping sound roller 5 is set in radius and length in the axial direction so as not to interfere with each other even when inserted into the pipe.

The four striking sound rollers 5 attached to the elastic support portions 3 and 4 have a bearing ball 5b embedded as a striking ball on the outer surface, and in the natural state before being inserted into the pipe, the bearing ball 5b The shapes and dimensions of the elastic support portions 3, 4 and the striking roller 5 are set so that the diameter of the circle formed by the outer end is larger than the inner diameter of the pipe by about 5 mm.
As a result, when inserting into the pipe, the arm portions 3d, 3e, 4d, 4e of the elastic support portions 3 and 4 are pushed inward in the state of being bent inward. In the pipe, of the bearing balls 5b embedded in the surface of each tapping roller 5, the one at the outermost end in the radial direction is pressed against the inner wall of the pipe with a predetermined elastic force, and is in the center. The shaft member 1 is maintained in a substantially centered state in the pipe.

If any of the arm portions 3d, 3e, 4d, and 4e bends according to the curvature of the pipe and interferes with the inner wall of the pipe while moving in the pipe, it causes noise. Therefore, in the inside of the pipe, the outer edges of the arm portions 3d, 3e, 4d, and 4e have a sphere or a center having almost the same radius as the inner wall of the pipe so that the pipe having a large curvature can move smoothly without interfering with the inner wall of the pipe. It is preferable that the shaft coincides with the central shaft member 1 and the vertical cross section at the center point is included in an elliptical sphere having a radius substantially the same as the inner wall of the pipe.

The elastic force of the arm portions 3d and 3e of the elastic support portions 3 and 4 is outside the striking roller 5 when the boss portion 3a of the elastic support portion 3 is towed by the tow cable in consideration of the friction coefficient of the inner wall of the pipe. The bearing ball 5b embedded in the surface is set so as not to slip on the inner wall of the pipe in the axial direction.
Further, in order to prevent the bearing ball 5b from slipping in the axial direction, after ensuring the contact of the bearing ball 5b, the striking roller so that a part of the outer surface of the striking roller 5 always directly contacts the inner wall of the pipe. The shape and arrangement of the bearing balls 5b may be selected.
For example, the outer surface of the striking roller 5 is brought into direct contact with the inner wall of the pipe at the apex or both ends of the central portion in the axial direction to prevent axial slippage, and the striking roller is reliably rotated and arranged on both sides in the axial direction. The striking sound may be made by the bearing ball 5b.
In the example of FIG. 2, the tapping roller 5 is partially brought into contact with the inner wall of the pipe at both ends in the rotation axis direction, the tapping roller 5 rotates reliably, and the bearing balls 5b arranged in a staggered pattern on the outer surface make the tapping sound. Is set to be performed.
In this case, the tapping roller 5 is preferably formed of a synthetic resin having a certain degree of elasticity and a sufficient friction coefficient with respect to the inner wall of the pipe.

A hook 6 is provided on the boss portion 3a of the elastic support portion 3, and a tow cable inserted from the opening on the other end side of the pipe is connected to this hook 6, and four striking sound rollers 5 are connected along with the towing. Rotates, and each bearing ball 5b collides with the inner wall of the pipe in sequence, and a tapping sound can be generated.
The tapping sound generated by the bearing ball 5b is detected by a commercially available sound collecting microphone 7 such as a condenser microphone mounted on the boss portion 4a of the rear elastic support portion 4. The sound collecting microphones 7 are preferably arranged in pairs so as to be directed in the vertical direction with respect to the normal of the pipe, and an audio cable extends behind the sound collecting microphones 7 and is connected to an analysis device described later.

The sound collecting microphone 7 can be installed at various locations such as the boss portion 4a of the rear elastic support portion 4, the boss portion 3a of the front elastic support portion 3, and the central shaft member 1. However, it is preferable to install it via a cushion material having high anti-vibration performance so as not to pick up noise due to vibration of the central shaft member 1. The wiring from the sound collecting microphone 7 is drawn out from the opening on the other end side of the pipe and connected to the analysis unit described later.

As an example, the behavior of the elastic support portions 3 and 4 when passing through the right-angled pipe is schematically shown in FIGS. 3 (a) and 3 (b).
In (a) immediately before the right-angled pipe, the elastic support portion 3 travels in the pipe while rotating with the front side in the traveling direction slightly lifted.
In (b), which has progressed to the right-angled pipe, the inner peripheral side of the right-angled pipe of the elastic support portion 3 comes into contact with the inner peripheral side corner of the right-angled pipe, and the posture is changed in the vertical direction from this as a starting point to form the vertical part of the right-angled pipe. You can make a smooth transition.
As shown in FIG. 4, when the central shaft member 1 is formed of a bendable elastic member or the central portion is connected by a universal joint, a smooth transition to the vertical portion of the right-angled pipe is performed. The central shaft member 1 may be bent. As a result, the inner diameter of the pipe is small, and smooth passage is possible even when the bend is steep.

As shown in FIG. 5, the sound collecting signal from the sound collecting microphone 7 is input to the analysis unit 8, recorded according to the position of the pipe based on the winding amount signal from the electric winder 9, and is acoustically analyzed. Is performed, and then the output is output to the display / output device 9.
As shown in FIG. 6, in front of the hitting sound unit composed of the elastic support portions 3, 4 and the hitting sound roller 5, a centering ball, a radial brush, and a plurality of curved ones whose radius substantially matches the radius of the inner wall of the pipe. It is made of an elastic member, and the radius of the circle connecting the apex is almost the same as the radius of the inner wall of the pipe, and a pop noise reduction cage that reduces pop noise due to contact with the inner wall of the pipe or contact with the wiring is connected. You may. As a result, it is possible to reduce the pitching of the striking sound roller 5, the fluctuation of the towing direction by the tow cable, and the generation of noise other than the striking sound.

The experimental results using the actually manufactured rolling type tapping mechanism will be described.
As the pipes to be tested, iron pipes with an inner diameter of 25 mm, an outer diameter of 35 mm (thickness of 5 mm), and a length of 150 cm are prepared. Was formed.
As a rolling type tapping mechanism corresponding to this piping, the length of the central shaft member 1 is 37.5 mm, the width formed by the outer peripheral end of the tapping roller 5 in a natural state is 28.5 mm, and the width of the tapping roller 5 is set. 10 mm, the outermost diameter of the tapping roller 5 is 10.5 mm (near the center), the elastic supports 3 and 4 are made of stainless spring material (thin plate thickness 0.2 mm), and the pressing force against the inner wall of the pipe is 1.5 N. Set to.
FIG. 7 shows the actually manufactured rolling-type tapping mechanism, which is for pipe inner diameters of 46 mm, 35 mm, and 25 mm in order from the left, and is the inner wall of the pipes of the elastic supports 3 and 4 made of stainless spring material. The pressing force against the pressure was set to 1.5 N in each case.
The tapping sound roller 5 was manufactured by a 3D printer using an epoxy resin (hard plastic).

When the towing speed of the towing cable was 8.5 cm / s to 15 cm / s, the acoustic data obtained by the sound collecting microphone 7 was recorded at 48 kHz and 32 bit sound quality, and the analysis was performed by the analysis unit 8. In the acoustic analysis, principal component analysis (PCA) and linear discriminant analysis (LDA) were used to verify whether or not the uncut portion (Normal) and the portion having a cutting depth of 1 mm, 2 mm, and 3 mm could be clustered.
FIG. 8 is based on the principal component analysis and does not necessarily show clear clustering, but in the linear discriminant analysis, as shown in FIG. 9, the uncut portion (Normal), the cutting depth of 1 mm, 2 mm, and 3 mm It was demonstrated that it can be clearly divided into four types and that even the degree of corrosion can be measured.

In the above embodiment, the two tapping sound rollers 5 supported by the elastic support portion 3 and the two tapping sound rollers 5 supported by the elastic support portion 4 are opposed to each other and are 90 degrees around the central shaft member 1. A total of four are arranged at intervals, but the point is that the tapping sound roller can move smoothly while rotating in the pipe, and it is sufficient to realize reliable tapping sound generation. Therefore, for example, a pipe with a small curvature, etc. Depending on the situation, only the elastic support portion 3 on the front side may be used, a hemispherical centering member may be combined, the elastic support portions 3 and 4 may be oriented in the same direction, or the axial direction of the tapping roller may be shortened to be on the same circumference. Various modes are conceivable, such as arranging four in.

Further, although the rotation axis of the hitting sound roller 5 is orthogonal to the axial direction of the central shaft member 1, it may be tilted as long as a sufficient rotational force with respect to the hitting sound roller can be obtained by the frictional force. In that case, since a rotational force is generated on the central shaft member 1, it is possible to make a striking sound with a spiral locus. However, as the central shaft member 1 rotates, a large twisting force may be generated in the wiring from the sound collecting microphone 7, so that the hook 6 may be rotated or the boss portions 3a and 4a of the elastic support portions 3 and 4 may be generated. It is necessary to take measures such as bearing the central shaft member 1 with a bearing or the like.

Further, a small illuminated camera for photographing the inner wall of the pipe may be installed on the central shaft member 1 so that the result of the acoustic analysis by the tapping roller 5 can be collated.
Further, the elastic roller may be miniaturized to have three or more elastic support portions, the base end portion of the elastic support portion 3 may be rotatable and adjustable, and the pressing force against the inner wall of the pipe may be optimized according to the inner diameter of the pipe. It may be possible to adjust to.

As described above, according to the present invention, even in the pipe bending portion, the striking roller is reliably rotated while elastically deforming so that the arm of the elastic support portion follows the inner wall of the pipe, and the cost is low and the size is small. Even for bent pipes with a diameter, it is possible to accurately inspect and diagnose the progress of corrosion over the entire length of the pipe, so it is expected to be widely used for inspection of various pipes in chemical plants. it can.

1 ... Central shaft member 2 ... Tow cable 3, 4, Elastic support 5 ... Striking sound roller 6 ... Hook 7 ... Sound collecting microphone 8 ... Analysis unit 9 ... Display・ Output device

Claims (4)

The central shaft member towed by the tow cable and
An elastic support portion mounted on the central shaft member and having an arm extending in the radial direction from the central shaft member.
It consists of a plurality of tapping sound rollers rotatably supported by the arm.
When inserted into the pipe, the arm of the elastic support portion causes N (N is a natural number of 2 or more) of the tapping rollers to be repressed in the circumferential direction every [360 / N] degrees, and the center. Centering is performed so that the central axis of the shaft member coincides with the central axis of the pipe, and
By inclining the rotation axis of the striking roller with respect to the central axis of the central shaft member, the striking roller is rotated around the rotating shaft with the pulling of the central shaft member, and is formed on the outer surface thereof. A rolling type tapping mechanism characterized in that the tapping ball provided is used to strike the inner wall of the pipe. The elastic support portion includes a boss portion mounted on the end portion of the central shaft member, and two base end portions extending from the boss portion in a direction orthogonal to the axial direction of the central shaft member. At the end of each base end portion, two arm portions curved in a plane orthogonal to each base end portion are provided, and the tapping sound roller is rotatably supported at both ends of the arm portion. The rolling tapping mechanism according to claim 1, wherein the two tapping rollers are opposed to each other. The boss portions are provided at both ends of the central shaft member, the rotation axes of the striking rollers supported by the respective arm portions are arranged so as to be orthogonal to each other, and the striking rollers are arranged in the circumferential direction with respect to the inner wall of the pipe. The rolling type tapping mechanism according to claim 2, wherein the cracking mechanism is made to be suppressed every 90 degrees. Inside the pipe, the outer edge of the arm portion is a sphere having substantially the same radius as the inner wall of the pipe, or a circle whose central axis coincides with the central shaft member and whose vertical cross section has substantially the same radius as the inner wall of the pipe. The rolling tapping mechanism according to claim 2 , wherein the mechanism is included in an ellipsoidal sphere.

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