JPH07227752A - Holding mechanism for in-pipe travel device - Google Patents

Abstract

PURPOSE:To enable holding mechanisms to exhibit a great bridging force through a simple structure by having a direction changing mechanism that converts displacement of the spindle of a main cylinder into displacement perpendicular thereto and a toggle mechanism, and causing a plurality of bridging arms to expand and contract in the radial direction of piping. CONSTITUTION:A reverse side bead removal system which grinds reverse side by running inside the piping 1 of a nuclear power plant or the like has an in-pipe travel device connected to the rear of a grinding device along the direction in which the grinding device moves, with in-pipe holding mechanisms 13 provided at the front and rear of the in-pipe travel device along the direction in which the travel device moves. The in-pipe holding mechanisms 13 each have a main cylinder 21 disposed approximately in the center of the inside of a main body casing 20 and along the direction of the axis of the piping, and the displacement of the spindle 21a of the main cylinder 21 in the direction of the piping axis is converted into the displacement of a supporting block 31 in the direction of the piping axis by a direction changing mechanism 22 that utilizes a wedge mechanism. By operation of a toggle mechanism 33 supported against the supporting block 31, bridging arms 32 mounted on the supporting block 31 are pressed into contact with the inner surface 1a of the piping, and thus the in-pipe travel device can be held inside the piping.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding mechanism for a traveling device in a pipe.

[0002]

2. Description of the Related Art In general, various pipes in a nuclear power plant, a thermal power plant or the like are sometimes subjected to repair work such as grinding and welding from the inner surface side. For example, in a pipe welded part of a nuclear power plant, the backside wave generated on the inner surface of the pipe interferes with the inspection during the service period.
It is necessary to eliminate such back waves to eliminate the geometric discontinuity on the inner surface of the pipe. By the way, in order to perform work such as repair on the inner surface of the pipe, it is necessary to insert various work equipment into the pipe and convey it to the work place.To this end, the work equipment must be towed by the in-pipe traveling device. Will be needed. Various types of such in-pipe traveling devices have already been proposed, and one of them is one that travels in a pipe by a Zen motion method. Conventionally, a Zen-motion type in-pipe traveling device is configured by connecting two holding mechanisms arranged side by side in the front-back direction in a traveling direction by an expansion / contraction mechanism such as a forward / rearward traveling cylinder. During this time (that is, during the stretched state), the operation of advancing the other holding mechanism by a predetermined stroke is repeated to intermittently travel in the pipe (for example, Japanese Patent Laid-Open No. 2-60875).

[0003]

However, in the conventional holding mechanism for the in-pipe traveling device, the pressing cylinders are radially arranged on the outer peripheral portion of the main body to be inserted into the pipe, and these pressing cylinders are operated. Therefore, there is a problem that the structure inevitably becomes large because the state of being bulged against the inner surface of the pipe is obtained. That is, since an extremely large traction force is required for the in-pipe traveling device that travels in the pipe, the holding mechanism thereof is required to have a sufficient tensile force commensurate with it. However, with the structure in which the pressing cylinders are arranged in the pipe radial direction (radial) as in the past, the size of the device becomes too large to obtain the required thrust force. It will not be possible to obtain the thrust force of.

The present invention has been made in consideration of the above circumstances, and an object thereof is to provide a holding mechanism for a traveling device in a pipe which can obtain a sufficiently large thrust with a small structure.

[0005]

In order to achieve the above object, a holding mechanism for a traveling device in a pipe according to the present invention is provided with a main body casing to be inserted into the pipe and a center line in the main body casing. A main cylinder, a direction changing mechanism for converting the displacement of the spindle of the main cylinder into a displacement in a direction orthogonal to the main cylinder, a main body casing provided at intervals in the circumferential direction, and the direction changing mechanism causes a pipe radial direction. And a toggle mechanism for pressing the protruding arms against the inner surface of the pipe.

Here, the direction changing mechanism includes a substantially cone-shaped main stopper which is concentrically attached to the spindle of the main cylinder, and a sub-radial member which is radially provided on the outer peripheral side of the main stopper and can reciprocate in the pipe radial direction. It is preferable that the projecting arm comprises a stopper, and the protruding arm is erected at the tip of the sub stopper. It is also preferable that the main stopper and the sub stopper are provided with stairs that can be meshed with each other, and that a preload spring is provided for keeping the stairs normally separated from each other.

Further, according to the present invention, a pair of holding mechanisms arranged in parallel at intervals in the tube axis direction are connected to each other by a forward / backward moving cylinder extending in the tube axis direction.

[0008]

According to the above construction, the displacement of the spindle of the main cylinder extending along the pipe axis direction is converted into the displacement of the projecting arm in the pipe radial direction by the direction changing mechanism, so that the main cylinder is simply operated. The tension arm can be brought into contact with the inner surface of the tube. Further, after the tension arm is brought into contact with the inner surface of the pipe, the toggle mechanism can be operated to further strongly push the tension arm against the inner surface of the pipe. In this way, by making the protruding arm contact the inner surface of the pipe by the single main cylinder extending in the pipe axis direction, the structure can be simplified and downsized as compared with the structure in which the cylinder is arranged in the pipe radial direction. You can Moreover, by further pressing the thrust arm with the toggle mechanism, a large thrust force can be obtained without increasing the size of the device.

Here, the direction changing mechanism comprises a substantially cone-shaped main stopper concentric with the main cylinder, and a plurality of sub-stoppers radially provided on the outer peripheral side of the main stopper.
If a protruding arm is provided upright on the tip of each sub-stopper, the structure can be simplified and downsized.

Further, if the main stopper and the sub stopper are formed with stairs which can be meshed with each other, and these stairs are separated by a preload spring, both stairs are meshed with each other when the projecting arm comes into contact with the inner surface of the pipe, and the toggle is engaged. It is possible to cancel the reaction force of the thrust force generated by the mechanism.

If the above-mentioned holding mechanisms are arranged side by side in the axial direction of the pipe and are connected to each other by a forward / backward traveling cylinder extending along the axial direction of the pipe, a very large traction force can be obtained with a small structure. It is possible to easily tow heavy equipment even in a small-diameter pipe.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, a system configuration to which this embodiment is applied will be described with reference to FIGS. 1 and 2.

FIG. 1 shows a backside wave removing system that travels in the pipe 1 to grind the backside wave. As shown,
This system is connected to a grinding device 2 for performing a grinding operation, an in-pipe traveling device 4 connected to a rear side in a traveling direction of the grinding device 2 via a spherical joint 3 (a connecting means), and a rear side of the in-pipe traveling device 4. It is mainly composed of a cable / hose group 5. The grinding device 2 has a TV camera, a grinder 6 and the like (not shown) mounted on the main body 7, and when the backside is confirmed by the TV camera, grinding by the grinder 6 is started. The in-pipe traveling device 4 includes the first and second in-pipe holding mechanisms 13, 1 arranged side by side in front of and behind the traveling direction.
4 are connected by a forward / backward moving cylinder 15 and a spherical joint 16. Here, the main body casing 20 of each of the in-pipe holding mechanisms 13 and 14 is provided with a plurality of protruding arms 32 that can be retracted at equal angular intervals in the circumferential direction. By pressing on the surface 1a, a state in which the tube inner surface 1a is bulged (position holding state) can be obtained.
Further, in front of the first in-tube holding mechanism 13 and in the rear of the second in-tube holding mechanism 14, the inner pipe surface 1a is formed.
Wheel mechanisms 17 and 18 for guiding to are attached. The cable / hose group 5 is for supplying a drive source to various devices mounted on the above-mentioned devices 2 and 4, and the in-pipe traveling device 4 travels while pulling the cable / hose group 5. .

In the system having the above construction, when grinding the backside wave, first, the in-pipe traveling device 4 is caused to travel to convey the grinding device 2 to the welded joint portion of the pipe 1. That is, as shown in FIG. 2 (i), first, the first in-tube holding mechanism 13 in the forward direction is brought into a projecting state, and in this state, the forward / backward moving cylinder 15 is contracted to the second in-tube holding mechanism in the rear. 14
Is moved forward by a predetermined stroke S (FIG. 2 (ii)). afterwards,
While the second pipe holding mechanism 14 is in the projecting state,
Release the protruding state of the pipe holding mechanism 13 (Fig. 2 (ii
i), (iv)). In this state, the forward / backward moving cylinder 15 is further extended to move the first pipe holding mechanism 13 to the predetermined stroke S.
It is moved forward (Fig. 2 (v)), and then the holding mechanism 13 is put into a projecting state (Fig. 2 (vi)). Thereafter, the above operation is repeated to alternately advance the first and second in-pipe holding mechanisms 13 and 14, whereby the in-pipe traveling device 4 travels intermittently.

While the in-pipe traveling device 4 is traveling, the TV camera mounted on the grinding device 2 observes the inner surface condition of the pipe 1 at any time. When the TV camera confirms the backside, the in-pipe traveling device 4 is stopped and the grinding work by the grinder 6 is started at the same time. That is, as shown by the arrow A in FIG. 1, the grinder 6 is moved radially outward of the pipe 1 to bring the grindstone 8 into light contact with the pipe inner surface 1a, and in this state, the grinder 6 is traversed in the pipe axial direction (arrow B) and turning in the circumferential direction (arrow C), the pipe inner surface 1a
The back wave protruding to the side is ground. In this way, when the back seam at the predetermined weld joint is ground, the in-pipe traveling device 4 is caused to travel again, and the grinding device 2 is conveyed to the next weld joint.

Next, a concrete example of the in-pipe holding mechanisms 13 and 14 applied to the in-pipe traveling device 4 will be described. In the following, only the in-pipe holding mechanism 13 on the front side in the traveling direction will be described, and the rear holding mechanism 14 will not be described because it has the same configuration.

The pipe holding mechanism 13 is, as shown in FIG.
A main body casing 20 inserted into the pipe 1, a main cylinder 21 arranged along the pipe axis at a substantially central portion in the main body casing 20, and a displacement of a spindle 21a of the main cylinder 21 in a direction orthogonal to the displacement ( A direction changing mechanism 22 for converting the displacement of the support block 31 (in the pipe radial direction), and a protruding arm 3 mounted on the support block 31 and contacting the pipe inner surface 1a.
2 and a toggle mechanism 33 for pressing the projecting arm 32 against the pipe inner surface 1a.

The body casing 20 is a substantially cross-shaped front plate 2.
0a and the rear plate 20b are arranged to face each other in the front and rear of the traveling direction, and the front plate 20a and the rear plate 20b are connected to each other by a connecting bar 20c (Fig. 3 (b)), which is small and lightweight. Is being promoted. The main cylinder 21 is
The bottom portion is attached to the inner surface of the rear plate 20b and extends along the center line of the main body casing 20. The direction changing mechanism 22 includes a substantially cone-shaped main stopper 23 that is concentrically attached to the spindle 21a of the main cylinder 21.
, And four sub-stoppers 24, 24, ... Provided on the outer peripheral side of the main stopper 23 at a pitch of 90 ° in the circumferential direction. Here, the main stopper 23 includes a mounting portion 23a fitted to the tip portion of the spindle 21a, and a mounting portion 23a.
From the outer circumference of the main cylinder 21 at a pitch of 90 ° in the circumferential direction.
And a slanted portion 23b that extends at a predetermined angle (here, 45 °), so to speak, the corners of the quadrangular pyramid are cut out so that the shape seen from the front has a substantially cross shape. (See Figure 3 (b)). The sub stopper 24 is guided inside the front plate 20a so as to be movable back and forth along the pipe radial direction. A taper surface 26 that can contact the taper surface 25 on the outer circumference of the main stopper 23 is formed on the base end side of the sub stopper 24. On the other hand, a support block 31 is attached to the tip of the sub stopper 24 with bolts or the like.

The support block 31 is guided between the front plate 20a and the rear plate 20b so as to be movable back and forth in the radial direction of the pipe, and is recessed toward the inner surface 1a of the pipe.
a is formed. In addition, return coil springs 30 and 30 are stretched between the pair of support blocks 31 and 31 located at 180 ° opposite to each other, and the sub stopper 2
4 and 24 are constantly urged toward the main stopper 23 side (center line side of the main body 20).

In the recess 31a of the support block 31, a protruding arm 32 extending in the pipe radial direction is provided. The projecting arm 32 is erected on the inner bottom of the recess 31 a so as to be linear with the sub stopper 24. When the sub stopper 24 is pushed up by the operation of the main cylinder 21, the projecting arm 32 is pushed up. The tip of the pipe contacts the inner surface 1a of the pipe. In particular, the strut arm 32 of this example
A flange 32a is fitted around the outer circumference of the pipe 32, and the base end side of the flange 32a is inserted into a blind hole formed in the block 31 in advance so that the projecting arm 32 can advance outward in the radial direction of the pipe 1. It has become. Further, a rubber-made contact plate 34 is attached to the tip of the projecting arm 32 in order to obtain a large frictional force with respect to the pipe inner surface 1a.

A toggle mechanism 33 for pressing the projecting arm 32 against the pipe inner surface 1a is housed in the recess 31a of the support block 31. Toggle mechanism 33
Is composed of a toggle cylinder 35 arranged substantially parallel to the main cylinder 21, and a pair of links 36, 36 for transmitting the force generated by the toggle cylinder 35 to the thrust arm 32. The base end of the toggle cylinder 35 is
The support block 31 is rotatably supported on the inner wall of the support block 31 about an axis O ₂ , so that the tip end side of the cylinder 35 can swing in the pipe radial direction. Link 36,36
Has one end rotatably supported at the tip of the spindle of the toggle cylinder 35 so as to be rotatable about an axis O ₃ parallel to the axis O _2, and the other ends of the links 36, 36 are respectively the projecting arm 32 and the support block. It is rotatably supported by 31. Here, the links 36, 36 form a predetermined angle α (FIG. 5), which is slightly smaller than 180 °, so that when the toggle cylinder 35 is operated, both links 3
6 and 36 are expanded to strongly push the projecting arm 32 against the pipe inner surface 1a.

In the pipe holding mechanism 13 of this embodiment, in addition, in order to cancel the reaction force of the urging force by the toggle mechanism 33, the tapered surfaces 25, 26 of the main / sub stoppers 23, 24 are stepped. Formed into a toothed taper portion. As shown in FIG. 4, these tooth-shaped tapered portions 25 and 26 are formed to have the same height and width. Further, a preload spring 27 is provided between the tooth-shaped tapered portions 25 and 26 to separate them. That is, the toothed taper portion 26 on the side of the sub stopper 24 is
A groove 28 having a predetermined length is formed along the inclination direction, and a preload spring 27 is mounted in the groove 28. The preload spring 27 is
It is formed in a substantially U shape, and the central portion is fixed to the inner bottom portion of the groove 28. On the other hand, the toothed taper portion 25 on the main stopper 23 side is formed with a long groove 29 at a position corresponding to the groove 28, and both ends of the preload spring 27 come into contact with the inner bottom portion of the groove 29. It is like this. That is, the center portion of the preload spring 27 contacts the inner bottom portion of the groove 28, and both ends contact the inner bottom portion of the groove 29, thereby keeping the toothed taper portions 25 and 26 in a separated state.

Next, the operation of the pipe holding mechanism 13 having the above structure will be described.

In the normal state, the main / sub stoppers 23, 24
The tooth-shaped tapered portions 25 and 26 are not meshed with each other by the biasing force of the preload spring 27. When the main cylinder 21 is operated in this state, the spindle 21 of the cylinder 21
a advances, the support block 31 is expanded by way of the main stopper 23 and the sub-stopper 24, and the projecting arm 3
2 contacts the pipe inner surface 1a. Here, the thrust arm 32
Since a rubber-made contact plate 34 is attached to the tip of the contact plate 34, the diameter of the auxiliary stopper 24 and the support block 31 is expanded until the contact plate 34 is compressed. When the contact plate 34 is compressed, the movements of the block 31 and the sub stopper 24 are restrained, but the main stopper 23 further advances against the biasing force of the preload spring 27, as shown in FIG. 4 (b). The preload spring 27 is crushed and the tooth-shaped tapered portions 25 and 26 mesh with each other.

When the toggle cylinder 35 is actuated in this state, as shown in FIG. 5, the links 36, 36 expand in accordance with the advance of the spindle of the cylinder 35, and the thrust arm 32 is further pushed out. It is strongly pressed against the pipe inner surface 1a. At this time, the inner surface 1 of the pipe is
Although a reaction force of a very large urging force acts from a, as described above, since the toothed taper portions 25 and 26 are already meshed with each other, the reaction force (force toward the center in the radial direction). Is
Balanced by pairs facing each other at 180 °, the main cylinder 21
It is not transmitted to the side.

The main cylinder 21 and the toggle cylinder 35 are driven backward when releasing the projecting state of the pipe holding mechanisms 13 and 14. Then, the main stopper 23 is retracted to disengage the tooth-shaped tapered portions 25 and 26 from each other,
After that, the diameter of the auxiliary stopper 24 is reduced and the protruding arm 32 is separated from the inner surface 1a of the tube.

As described above, according to the pipe holding mechanism 13 of this embodiment, after the protrusion arm 32 is brought into contact with the pipe inner surface 1a by the main cylinder 21 arranged along the center line of the main body casing 20, Since the toggle mechanism 33 further presses the thrust arm 32, it is possible to obtain a smaller and larger thrust force as compared with the conventional structure in which the pressing cylinder is arranged in the radial direction. That is, since a large thrust force is obtained by the small toggle mechanism 33, the main cylinder 21 has only to obtain a stroke until the thrust arm 32 is lightly contacted with the pipe inner surface 1a, and a large force is not required. . For this reason, the main cylinder 21 is downsized, and by extension, the pipe holding mechanisms 13, 1
The size of 4 itself can be reduced.

Moreover, the main cylinder 21 extending in the pipe axis direction
By converting the displacement of the spindle 21a of the above into the diameter expansion / contraction of the plurality of projecting arms 32 by the direction changing mechanism 22, these projecting arms 32 are moved in synchronization with each other, and the pipe holding mechanism 13 is centered. be able to. As a result, the stable holding state of the pipe holding mechanism 13 can be maintained.

Further, according to the pipe holding mechanism 13 of the present embodiment, the stepped tooth-shaped tapered portions 25 and 26 are formed on the tapered surfaces of the main and auxiliary stoppers 23 and 24, respectively, and
By providing the preload spring 27 that separates the tooth-shaped tapered portions 25 and 26 from each other between the auxiliary stoppers 23 and 24, it is possible to balance the reaction force of the large thrust force generated by the toggle mechanism 33. That is, by engaging the toothed taper portions 25 and 26 with each other prior to the operation of the toggle mechanism 33, the reaction force of the thrust force generated by the toggle mechanism 33 is not transmitted to the main cylinder 21, and the spindle of the main cylinder 21 is prevented. No force is generated to push back 21a in the tube axis direction. Therefore, while maintaining the urging force of the toggle mechanism 33,
The main cylinder 21 can be downsized, and the pipe holding mechanism 13 itself can be downsized.

Furthermore, the auxiliary stopper 24 and the toggle mechanism 3
3 and the protruding arms 32 are provided on the outer peripheral side of the main stopper 23 at a pitch of 90 °, the protruding arms 32, 32 opposite to each other by 180 ° come into contact with the inner surface of the pipe, and at the same time, the entire movement stops. Even if the protruding arm 32 approaches the hole, it does not fall into the hole and the pipe 1
You can continue running inside.

In addition, the pipe holding mechanisms 13 and 14 having the above structure
By using, the structure of the in-pipe traveling device 4 itself can be downsized and the traction force can be increased, which is extremely useful as an in-pipe traveling device for small-diameter pipes.

[0033]

According to the first aspect of the present invention, after the main arm arranged along the center line of the main body casing makes the protruding arm abut against the inner surface of the pipe, it is further pressed by the toggle mechanism. Compared with the conventional structure in which cylinders are arranged in the radial direction of the pipe, a larger thrust force can be obtained with an extremely small structure.

According to the second aspect, the spindle displacement of the main cylinder is converted into the displacement of the projecting arm via the cone-shaped main stopper and the sub-stopper provided around the main stopper, so that the structure is extremely simple. Miniaturization can be achieved.

According to the third aspect of the present invention, since the step mechanism of the main and sub stoppers is engaged with the toggle mechanism prior to operation,
It is possible to reduce the size of the main cylinder and thus the internal pipe mechanism without transmitting the reaction force of the urging force from the inner surface of the pipe to the main cylinder.

According to the fourth aspect, it is possible to obtain a small size and a very large traction force.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a backside wave removing system to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a traveling operation of an in-pipe traveling device in the backwater removing system.

FIG. 3 is a schematic configuration diagram showing an embodiment of a holding mechanism of the in-pipe traveling device.

FIG. 4 is a view showing a main part of a direction changing device applied to a holding mechanism.

FIG. 5 is a view for explaining the action of the toggle mechanism applied to the holding mechanism.

[Explanation of symbols]

 1 Pipe 1a Pipe Inner Surface 4 Pipe Traveling Device 13,14 Pipe Holding Mechanism 15 Forward / Backward Traveling Cylinder 21 Main Cylinder 22 Direction Change Mechanism 23 Main Stopper 24 Sub-Stopper 25, 26 Toothed Tapered Part 32 Protruding Arm 33 Toggle Mechanism 35 Toggle Cylinder 36 Link

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiromi Yamazaki, 1 Higashishinmachi, Higashi-ku, Nagoya-shi, Aichi Chubu Electric Power Co., Inc. Headquarters Annex Building (72) Teruaki Sato, 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Ceremony company Toshiba Yokohama Works (72) Inventor Kazuo Saito 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries, Ltd. Yokohama First Factory (72) Inventor Mitsuo Ohno 1 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Chome 9-4 Ishikawajima Inspection & Measurement Co., Ltd. Yokohama No. 2 Plant (72) Inventor Manabu Nakamura 1-9-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa Ishikawajima Inspection & Measurement Co., Ltd. Yokohama No. 2 Plant

Claims (4)

[Claims] 1. A main body casing to be inserted into a pipe, a main cylinder arranged along the center line in the main body casing, and a displacement of a spindle of the main cylinder are converted into a displacement in a direction orthogonal thereto. A direction changing mechanism, a plurality of projecting arms which are provided in the main body casing at intervals in the circumferential direction thereof, and which are expanded and contracted in the pipe radial direction by the direction changing mechanism, and these projecting arms are provided in the pipe. A holding mechanism for an in-pipe traveling device, comprising: a toggle mechanism for pressing the surface. 2. The direction changing mechanism includes a substantially cone-shaped main stopper that is concentrically attached to a spindle of the main cylinder, and a sub-radial member that is radially provided on an outer peripheral side of the main stopper and can reciprocate in a pipe radial direction. The holding mechanism for the in-pipe traveling device according to claim 1, wherein the holding arm comprises a stopper, and the projecting arm is erected at a tip of the sub stopper. 3. The main stopper and the sub-stopper are formed with stairs which can be meshed with each other, and a preload spring for separating the stairs from each other is provided between the stoppers. A holding mechanism for the in-pipe traveling device described. 4. A pair of holding mechanisms arranged in parallel at intervals in the tube axis direction are connected to each other by a forward-backward traveling cylinder extending in the tube axis direction. Holding mechanism for in-pipe traveling device.