JP4653670B2 - Piping work device and work method - Google Patents

Description

  The present invention relates to an in-pipe work apparatus and work method for performing operations such as cleaning, inspection, inspection, preventive maintenance, and repair of an inner surface of a pipe installed in a nuclear power plant or the like, and in particular, installed in a reactor pressure vessel. The present invention relates to an in-pipe work apparatus and work method suitable for performing the above work on a weld line of a jet pump.

  In the inspection and inspection work inside the jet pump in the reactor water, a system (non-disassembly inspection) that sends the work equipment without removing the jet pump inlet mixer is proposed to reduce the number of work steps and work time. In most of the known techniques, the work device is fixed / held by a plurality of arms that can be deployed in the radial direction.

  As an example of such an inspection / inspection device in a jet pump, a working device has been invented in which a plurality of arms are radially deployed from an elongated casing and held in a pipe (see Patent Document 1). In the present invention, a pair of arms driven by an air cylinder are deployed with respect to the inner surface of the pipe in order to position the work unit including the scraper on the inner surface of the pipe and the suction port on the inner surface of the pipe.

As another example, there has been invented a working device that similarly deploys a plurality of guide arms in a radial direction from an elongated casing and holds the position in the pipe (see Patent Document 2). In the present invention, a detector is provided at the tip of a tripod that expands mechanically, and is expanded and fixed in three directions inside the pipe. Thereafter, the cable is rotated inside the pipe with the fixed side. In this device, a weight for posture stabilization is connected to the lower end, and it can be installed in parallel with the axis.
JP 2001-281386 A JP 2001-65778 A

  As described above, most of the conventional pipe working devices have a mechanical deployment structure as a structure for fixing and holding the position of the device inside the pipe. Such a mechanically deployed structure has a high risk of being unrecoverable due to poor recoverability in an emergency, and has a high risk of damaging piping such as a jet pump inlet mixer even if it can be recovered.

  The present invention has been made to solve the above-described problems, and provides an in-pipe working device and a working method that are easy to install and collect in a pipe with a simple configuration and have a low risk of damaging the pipe. The purpose is to do.

In order to solve the above-described problems, an in-pipe work apparatus according to the present invention includes a work head that performs work on the pipe from the inside of the pipe, and an expansion body that is provided in the pipe and expands by gas injection. A support device that supports a work head, and the expansion body includes a body portion formed of an elastic body, end plugs provided at both ends of the body portion, and end plugs at both ends in the body portion. A coil spring provided therebetween, and a central rod fixed to one of the end plugs and moving from the other end plug through the center of the coil spring are provided .

The work method in a pipe of the present invention includes a support device provided with an expansion body, a device insertion step of inserting a work head supported by the support device into the pipe, and a gas to the expansion body inserted into the pipe. An apparatus fixing step of injecting and inflating to bring the surface of the expanding body into contact with the inner surface of the pipe and fixing the support device at a predetermined position in the pipe, and an operation for performing an operation on the inner surface of the pipe with the work head A step of supplying the gas to the inside of the expansion body, inflating the expansion body by an internal pressure, and compressing a coil spring along a central rod present in the expansion body. And an expansion body contraction step for extracting the gas supplied to the expansion body and contracting the expansion body by being pushed back along the central rod by the coil spring after the construction step. And how to.

  ADVANTAGE OF THE INVENTION According to this invention, the installation and collection | recovery in piping are easy by simple structure, and the working apparatus in piping and working method which work can be provided, without damaging piping.

  Hereinafter, first to fourth embodiments of an in-pipe work method and apparatus according to the present invention will be described with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the in-pipe work apparatus according to the present embodiment includes a work head 17 that is inserted into the vertical pipe 10 and a support device 1 that supports the work head 17. The support device 1 includes a balloon (balloon) 2 which is an inflating body connected to a cable and tube bundle 11, and the working head 17 includes a rotation mechanism 13 connected to the central rod 6 of the balloon 2 by a universal joint 12, and A casing 14 coupled to the rotation mechanism 13 is provided. A camera 15 with illumination and a reflection mirror 16 are attached to the casing 14.

  As shown in FIG. 2, the balloon 2 has end plugs 3 a and 3 b attached to both ends of a body portion 4 that has a symmetrical shape around an axis and whose diameter increases when air is blown. A central rod 6 having one end fixed to the end plug 3a is provided at the central axis of the body portion 4, and the center rod 6 is inserted into a coil spring 5 having both ends fixed to the end plugs 3a and 3b. . The center rod 6 passes through the end plug 3b, and an O-ring 8 that slides with the center rod 6 is provided inside the end plug 3b. An air tube 7 for blowing air into the balloon 2 is connected to the end plug 3a.

  As shown in FIG. 2B, the body portion 4 has a shape in which a cross section in a direction orthogonal to the axis is symmetric and uneven around the axis. In this embodiment, the shape has six convex portions and six concave portions. When the body 4 is unfolded, six pieces of elastic bodies such as rubber in the shape of a leaf having a central valley fold as shown in FIG. 2C are integrally formed by adhesion or fusion. The portion corresponds to the concave portion in FIG. 2B, and the joint portion of each elastic piece corresponds to the convex portion.

  Now, when air is supplied to the inside of the balloon 2 through the air tube 7, the balloon 2 is inflated by the internal pressure, and the diameter of the central portion of the body portion 4 is increased as shown in FIG. 6, the coil spring 5 is compressed and contracted. The balloon 2 is inflated inside the pipe which is a work object such as inspection, and the outer periphery of the body 4 is brought into contact with the inner peripheral surface of the pipe, thereby fixing the support device 1 inside the pipe and supporting it against external force. be able to. Since the balloon 2 is symmetrical about the axis, the center rod 6 is always held at the center of the pipe. In order to return the balloon 2 to its original state, it is only necessary to remove the supplied air, and the end plug 3b is pushed back along the central rod 6 by the coil spring 5 to cause the balloon 2 to contract. When this pipe working device is used underwater, for example, if it is 15 m underwater, a water pressure of 0.15 Mpa acts from the outside, and the balloon 2 can be reliably deflated by receiving this water pressure.

  Specifically, referring to FIG. 1, the support device 1 suspended from the cable and tube bundle 11 inside the vertical pipe 10 is supplied with air to the balloon 2 and inflated to be fixedly supported inside the vertical pipe 10. Is done. The universal joint 12 can be bent in two directions orthogonal to the axis at the tip of the support device 1. The work head 17 is rotated 360 ° around the axis by the rotation mechanism 13, and the entire inner surface of the vertical pipe 10 is imaged by the camera 15 with illumination and the reflection mirror 16.

Although FIG. 1 shows a straight pipe, even if there is a bent pipe such as an elbow in front of the straight pipe, it is bent at the universal joint 12 by being pushed in with a flexible rod bundled together with the cable and the air tube 11. So you can let the curved pipe pass. Then, due to the dead weight of the work head 17, the axis of the work apparatus and the axis of the pipe are parallel to each other. In this state, air is supplied to the balloon 2 to fix the support device 1, thereby fixing the work head 17 to the pipe axis. It can be fixed to the center of the pipe. Then, by rotating the casing 14 by the rotation mechanism 13, it is possible to perform a circumferential inspection operation on the inner surface of the pipe.
By such an operation, for example, the working device can be fed from the nozzle opening and the inner surface can be visually inspected without removing the inlet mixer of the jet pump.

  According to the present embodiment, for example, when the inside of a pipe is inspected without removing the inlet mixer of the jet pump, the inner surface of the pipe is inspected by feeding the working device in the pipe from the nozzle opening of the inlet mixer. After the working device in the pipe is inserted into the pipe, the balloon 2 is inflated by supplying air from the air tube 7, and the work head 17 is fixed to and supported by the pipe inner surface parallel to the axis and in the center of the pipe. . When the working device is collected or moved to be inspected, the air supplied from the air tube 7 is discharged, so that the coil spring 5 and the external water pressure naturally contract. Since the balloon 2 is made of an elastic body such as rubber, there is a low risk of damaging the nozzle portion of the inlet mixer and the inner surface of the jet pump when the working device is recovered. Even if this air discharge line is blocked and air cannot be discharged, the air can be discharged by opening a hole in the balloon 2 with a pointed rod or the like, and the balloon 2 is deflated. Can do.

  As described above, according to the present embodiment, it is possible to configure a small size because it has a simple structure when the inside of the pipe is inspected without removing the inlet mixer of the jet pump provided in the nuclear reactor. It is possible to provide an in-pipe work device that is easy and has excellent insertability and recoverability. Further, it has a low risk of damaging the inner surface of a jet pump or the like, and has an excellent emergency recoverability and a low risk of being impossible to recover.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is an in-pipe inspection apparatus suitable for elbow piping (curved pipe). As shown in FIG. 3A, the working head 17 is connected to the flexible rod, cable, and tube bundle 20, and two balloons 2 of the supporting device 1 are connected to the working head 17 in series. The working head 17 is connected to the end plug 3 b of the balloon 2 by the coil spring 21, and the end plug 3 a of the same balloon 2 is connected to the end plug 3 a of the other balloon 2 by the coil spring 21. That is, in the connection between the balloons 2, end plugs 3 a that the central rod 6 does not penetrate are connected. Further, a hollow member 22 into which the center rod 6 is inserted and fitted is disposed at the connection portion of the work head 17.

  In this way, the in-pipe work device in which the support device 1 and the work head 17 are connected in series is pushed from the straight pipe portion of the elbow pipe 23 by the flexible rod, the cable, and the tube bundle 20 as shown in FIG. The elbow pipe 23 is installed in the horizontal pipe section. Although it passes through the bent portion, the connecting portion between the support device 1 and the working head 17 and the connecting portion between the balloons 2 are flexibly deformed by the coil spring 21 and the whole can be bent and pass. Thereafter, the balloon 2 is inflated by supplying air from the flexible rod, cable, and tube bundle 20 and fixed inside the elbow pipe 23. At this time, since the balloons 2 are connected in opposite directions, the central rod 6 on the distal end side jumps out to the distal end side, and the central rod 6 on the working head 17 side jumps out to the working head 17 side. And it fits in the hollow member 22 attached to the working head 17, and the working head 17 is supported horizontally on a piping axis.

With the above operation, the work head 17 is supported at the center parallel to the pipe axis with respect to the welded portion 24 between the bent portion of the elbow pipe 23 and the horizontal pipe. And the inspection of the welding part 24 is performed over the perimeter of piping inner side by rotating the direction of the illumination light 28 by the rotation mechanism 13 which is not shown in figure in the working head 17. FIG.
According to the in-pipe work apparatus of the present embodiment, it is possible to perform a good in-pipe work with good workability without damaging the pipe or making the apparatus unrecoverable.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. The in-pipe work apparatus of the present embodiment is provided with an inspection sensor 25 that is a contact-type work head at a portion that contacts the inner surface of the vertical pipe 10 of the balloon 2 that constitutes the support apparatus 1, and a universal joint 12 is provided at the lower part. The weight 26 is connected.

In the present embodiment, the in-pipe work device is suspended from the vertical pipe 10 to enter the pipe. Since the weight of the weight 26 causes the axis of the working device to be parallel to the axis of the pipe 10, in this state, air is supplied to the balloon 2 to inflate the balloon 2, and the inspection sensor 25 contacts the inner surface of the pipe 10. Let Next, the inspection mechanism 25 is scanned in the circumferential direction by rotating the entire working device with the rotation mechanism 13 using the cable and tube bundle 11 as a fixed side. The collection method and other operations are the same as those in the first embodiment.
According to the present embodiment, a contact type ultrasonic sensor or the like can be scanned along the circumference perpendicular to the pipe axis on the inner surface of the pipe to perform work such as inspection.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG. In the in-pipe work apparatus of the present embodiment, the support apparatus 1 includes three balloons 27a, 27b, and 27c that are inflated with air in the radial direction, and these balloons are arranged at 120 degrees. Below that, a work head 17 is connected via a universal joint 12. The balloons 27a, 27b, and 27c are made of an elastic body made of rubber or the like.

  The working device suspended from the cable and tube bundle 11 is suspended in parallel with the axis of the vertical pipe 10 by the weight of the work head 17, and in this state, from the cable and tube bundle 11 to the inside of the balloons 27a, 27b, and 27c. By supplying air, each balloon inflates and expands in three directions and contacts the inner surface of the pipe 10. Thereby, the working device can be fixedly supported inside the pipe. In order to contract the balloons 27a, 27b, and 27c, the air supplied by the cable and tube bundle 11 may be released, and the balloons 27a, 27b, and 27c can be contracted by the contraction force of an elastic body such as rubber. In addition, when the working device of the present embodiment is used in water in which water head pressure acts, it can be contracted by water pressure from the outside, and can be reliably contracted.

  According to the present embodiment, when the inside of the pipe is inspected without removing the inlet mixer of the jet pump provided in the nuclear reactor, the inner surface is inspected by feeding the work device from the nozzle opening of the inlet mixer. Is possible. Further, since the balloons 27a, 27b, and 27c are made of an elastic body such as rubber, there is a low risk of damaging the nozzle portion of the inlet mixer and the inner surface of the jet pump when the working device is recovered. Even if the air discharge line from the balloon is blocked and the air cannot be discharged, the air can be discharged by opening a hole with a pointed rod or the like in the balloons 27a, 27b, 27c, The balloon can be deflated.

  As described above, according to the present embodiment, it is possible to configure a small size because it has a simple structure when the inside of the pipe is inspected without removing the inlet mixer of the jet pump provided in the nuclear reactor. It is possible to provide an in-pipe work device that is easy and has excellent insertability and recoverability. Further, it has a low risk of damaging the inner surface of a jet pump or the like, and has an excellent emergency recoverability and a low risk of being impossible to recover.

  In the first to fourth embodiments described above, the case of inspection and inspection work is described as an example of work in piping, but the work head that performs inspection and inspection may be replaced with the work head that performs other work. Similar effects can be obtained. That is, it may be a cleaning device such as a brush or a polishing jig, a water cleaning nozzle, a preventive maintenance device such as a water jet peening head or a laser peening head, or a repair device such as a welding head or a grinding jig. Further, an inert gas such as nitrogen gas may be injected into the balloon instead of air.

The elevational view which shows the structure of the working apparatus in piping of the 1st Embodiment of this invention, and the installation condition in piping. The balloon which comprises the working apparatus in piping of the 1st Embodiment of this invention is shown, (a) is a sectional elevation, (b) is sectional drawing which follows the bb line of (a), (c) is A developed view of the body part, (d) is an elevational sectional view showing an expanded state. The work apparatus in piping of the 2nd Embodiment of this invention is shown, (a) is the figure which shows at the time of insertion in elbow piping, (b) is the time of installation in elbow piping. The elevation view which shows the structure of the working apparatus in piping of the 3rd Embodiment of this invention, and the installation condition in piping. The elevation view which shows the structure of the working apparatus in piping of the 4th Embodiment of this invention, and the installation condition in piping.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Support apparatus, 2 ... Balloon, 3a, 3b ... End plug, 4 ... Body part, 5 ... Coil spring, 6 ... Center rod, 7 ... Air tube, 8 ... O-ring, 10 ... Vertical piping, 11 ... Cable and tube Bundle, 12 ... Universal joint, 13 ... Rotating mechanism, 14 ... Casing, 15 ... Illuminated camera, 16 ... Reflecting mirror, 17 ... Working head, 20 ... Flexible rod and cable and tube bundle, 21 ... Coil spring, 22 ... Hollow member 23 ... Elbow piping, 24 ... Welded part, 25 ... Inspection sensor, 26 ... Weight, 27a, 27b, 27c ... Balloon, 28 ... Illumination light, 29 ... Support rod.

Claims (4)

A work head that performs work on the pipe from the inside of the pipe, and a support device that has an expansion body provided in the pipe and expands by gas injection, and supports the work head ,
The inflatable body includes: a body portion formed of an elastic body; end plugs provided at both ends of the body portion; a coil spring provided between the end plugs at both ends in the body portion; An in-pipe working apparatus comprising: a center rod fixed to a stopper and moving from the other end stopper through the center of the coil spring . It said support device comprises a plurality of said expansion member, according to claim 1 wherein the plurality of expansion body, characterized in that an elastic member is interposed are coupled to one another between the end plug between which is fixed the central rod In-pipe working device. The in-pipe work apparatus according to claim 1, wherein an inspection sensor is disposed at a contact portion between the expansion body and the inner surface of the pipe. An apparatus insertion step for inserting a support device including an inflating body and a work head supported by the support device into the pipe;
A device fixing step of injecting a gas into the expansion body inserted into the pipe and expanding the gas to expand the surface of the expansion body to contact the inner surface of the pipe and fixing the support device at a predetermined position in the pipe;
A construction process for performing work on the inner surface of the pipe by the work head ,
The device fixing step includes an expansion body expansion step in which a gas is supplied to the inside of the expansion body to expand the expansion body by internal pressure, and a coil spring is compressed along a central rod present in the expansion body,
An in-pipe work method comprising: an expansion body contraction process for drawing the gas supplied to the expansion body after the construction step and contracting the expansion body by being pushed back along the central rod by the coil spring. .

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