Repair device and repair method

This repair device includes a casing, a slide shaft slidably arranged with respect to the casing, a turn table rotatably arranged with respect to the slide shaft, a cutting mechanism installed on the turn table and including a cutting tool, and an advancing and retracting mechanism that displaces a radius of rotation of the cutting mechanism with respect to rotations of the turn table forward and backward. In a state where the casing is centered and positioned with respect to the pipe, the turn table is rotationally displaced while the slide shaft slides in an axial direction, and the advancing and retracting mechanism displaces the cutting mechanism forward and backward. Accordingly, the cutting tool helically turns along an inner peripheral shape of the pipe to cut an inner periphery of the pipe.

FIELD

The present invention relates to a repair device and a repair method, and more particularly to a repair device and a repair method that can streamline a repairing operation.

BACKGROUND

In a nuclear plant, a repairing operation for repairing a welded part between a nozzle and a pipe in a reactor containment is performed to ensure safety and reliability thereof. As a repair device used for such a repairing operation, a technique described in Patent Literature 1 has been known.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

An object of the present invention is to provide a repair device and a repair method that can streamline a repairing operation.

Solution to Problem

According to an aspect of the present invention, a repair device that repairs a welded part on an inner peripheral side of a pipe, includes: a casing; a slide shaft slidably arranged with respect to the casing; a turn table rotatably arranged with respect to the slide shaft; a cutting mechanism installed on the turn table and including a cutting tool for cutting the welded part; and an advancing and retracting mechanism that displaces a radius of rotation of the cutting tool with respect to rotations of the turn table forward and backward by displacing the cutting mechanism forward and backward. In a state where the casing is positioned with respect to the pipe, the turn table is rotationally displaced while the slide shaft slides in an axial direction, and the advancing and retracting mechanism displaces the cutting tool forward and backward, so that the cutting tool helically turns along an inner peripheral shape of the pipe to cut an inner periphery of the pipe.

In this repair device, turning cutting by the cutting tool is realized by an interaction among sliding displacement of the slide shaft, rotational displacement of the turn table, and forward and backward displacement of the cutting tool. With this configuration, because an area to be cut having a substantially cylindrical shape can be cut smoothly, cutting accuracy is improved. Accordingly, aftertreatment is not required, and thus a repairing operation can be streamlined.

Advantageously, the repair device further includes a measuring unit that acquires measurement data of the inner peripheral shape of the pipe. A relation among a sliding speed of the slide shaft, a rotational speed of the turn table, and a speed of forward and backward displacement of the cutting mechanism is calculated based on the measurement data and a predetermined cutting depth, thereby controlling a turning trajectory of the cutting tool.

This repair device can perform cutting with respect to an area to be cut along the inner peripheral shape of the pipe (profile copy turning cutting). Accordingly, an area to be cut having a non-uniform shape can be cut accurately.

Advantageously, the repair device further includes a buff mechanism including a buff for buffing. The buff mechanism and the cutting mechanism are switchably installed on the turn table.

In this repair device; the repair device serves as the buff mechanism and the cutting mechanism, and therefore there is an advantage in that operations related to transporting in/out and installation of the device can be omitted, as compared to a configuration in which the buff mechanism and the cutting mechanism are separately used.

Advantageously, in the repair device the advancing and retracting mechanism displaces the buff mechanism forward and backward, thereby displacing a radius of rotation of the buff mechanism with respect to rotations of the turn table forward and backward.

In this repair device, buffing can be performed by revolving the buff helically (or stepwise on a circumference) while in rotation, by an interaction among sliding displacement of the slide shaft, rotational displacement of the turn table, and forward and backward displacement of the buff mechanism. Accordingly, buffing can be smoothly performed with respect to an area to be buffed having a substantially cylindrical shape.

Advantageously, the repair device further includes a clamp mechanism that holds the casing in a state where the casing is positioned with respect to the pipe.

In this repair device, the clamp mechanism appropriately holds a position of the casing (particularly, a relative position of the repair device in an axial direction of the pipe with respect to a target to be cut) at the time of controlling a turning trajectory of the cutting tool, and therefore the repair device is installed in the pipe in a self-standing manner. Accordingly, a plurality of repair devices can be respectively installed in a plurality of pipes and operated independently, thereby enabling to streamline a repairing operation.

According to another aspect of the present invention, a repair method of repairing a welded part on an inner peripheral side of a pipe, includes: a measuring step of acquiring measurement data of an inner peripheral shape of the pipe; and a cutting step of performing profile copy cutting with respect to an inner periphery of the pipe, while helically turning a cutting tool along the inner peripheral shape of the pipe, based on a relation between the measurement data and a predetermined cutting depth.

According to this repair method, because cutting (profile copy turning cutting) can be performed with respect to an area to be cut along the inner peripheral shape of the pipe, an area to be cut having a non-uniform shape can be cut accurately. Accordingly, aftertreatment is not required, and thus a repairing operation can be streamlined.

Advantageous Effects of Invention

According to the repair device and the repair method of the present invention, the repair device realizes turning cutting by the cutting tool by an interaction among sliding displacement of the slide shaft, rotational displacement of the turn table, and forward and backward displacement of the cutting tool. With this configuration, an area to be cut having a substantially cylindrical shape can be cut smoothly, thereby improving cutting accuracy. Accordingly, aftertreatment is not required, and thus a repairing operation can be streamlined.

DESCRIPTION OF EMBODIMENTS

The present invention is explained below in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiment. In addition, constituent elements in the embodiment include elements that can be easily replaced or obviously replaceable while maintaining the unity of invention. A plurality of modifications described in the following embodiment can be arbitrarily combined within a scope obvious to persons skilled in the art.

[Repairing Process of Reactor Containment]

FIG. 17is a flowchart of a repairing process of a reactor containment.FIG. 18is an explanatory diagram of a welded part between a nozzle and a pipe in the reactor containment.

In a reactor containment100, maintenance is regularly performed to ensure safety and reliability thereof. For example, the reactor containment100includes a nozzle120provided on a side of an outer periphery of a containment main body110and a cooling water pipe (an inlet pipe or an outlet pipe)130(seeFIG. 18). The nozzle120and the pipe130have a substantially cylindrical inner periphery and are connected by welding from at least one of the inner peripheral side and the outer peripheral side. Generally, the nozzle120and the pipe130are made of a material different from each other, and welded by nickel based alloy600. Maintenance such as a repairing operation is required for a welded part between the nozzle120and the pipe130. As an example, a case where a repairing operation is performed at a welded part X on the inner peripheral side of the nozzle120and the pipe130is explained.

First, as a preparation step (Step ST1), a work table140having a cylindrical container shape is inserted into the containment main body110and installed therein. The work table140transports various types of repair devices required for a repairing operation (an inspection device, a cutting device, a welding device, and a buff device described later) into the nozzle120, and has an opening141at a position corresponding to the nozzle120. A gap between the containment main body110and the work table140is then sealed and joined by using a flange. Subsequently, cooling water below the flange is discharged, and a water level of cooling water is set such that the water level becomes at least below the nozzle120of the containment main body110(seeFIG. 17andFIG. 18). A shield150is inserted into the nozzle120from the opening141of the work table140and installed therein. The shield150is a member that fills a gap between the opening141of the work table140and the nozzle120and extends the opening141to the inner periphery of the nozzle120. The shield150forms a cylindrical inner wall surface (an installation space of the repair device) extending from the opening141of the work table140to the welded part X of the nozzle120. A stopper (not shown) is installed on an inner side of the pipe130to form a seal for blocking radiation and preventing dispersion of foreign substances.

Next, a device-transporting jig (not shown) is installed (Step ST2). The device-transporting jig transports the repair device and is installed at the bottom of the work table140. For example, the device-transporting jig is formed by a turn table having a telescopic arm. When the repair device is transported into the welded part X, the repair device is suspended in the work table140, and the device-transporting jig transports the repair device into the nozzle120and installs the repair device in the nozzle120. At this time, the device-transporting jig holds the repair device by the arm, and extends the arm to insert the repair device into the nozzle120from the opening141of the work table140. Accordingly, the repair device is transported into the nozzle120. Thereafter, the device-transporting jig is detached from the repair device, contracts the arm, and is returned to an original position. On the other hand, when the repair device is to be removed from the welded part X, the device-transporting jig extends the arm again to hold the repair device in the nozzle120, contracts the arm, and recovers the repair device into the work table140. The repair device is then hoisted and transported to outside of the work table140. With these processes, transporting in/out of the repair device is performed.

Next, an ultrasonic testing (UT) using ultrasonic waves is performed (inspection step ST3). The UT is a test for acquiring required data of the welded part X (for example, data relating to the presence and position of a defect in the welded part X). At Step ST3, an inspection device for performing the UT (not shown) is transported in by the device-transporting jig and installed near the welded part X of the nozzle120. The inspection device performs the UT to acquire necessary inspection data. For example, the inspection data includes a position of the welded part X, a position of a large crack generated in the welded part X (a crack requiring local cutting described later) and the like. The acquired inspection data is transmitted from the inspection device to a controller (not shown) in a monitoring facility located outside of the reactor containment100. Furthermore, the inspection device punches a mark near the welded part X, for indicating the position of the welded part X or the position of a crack. Thereafter, the inspection device is transported out of the nozzle120and then recovered.

Next, local cutting is performed according to need (local cutting step ST4).FIG. 19is an explanatory diagram of a state of a local cutting. The local cutting is for locally and deeply cutting a cracked portion in the welded part X, when there is a large crack in the welded part X. In the local cutting, a cutter10for cutting is used (seeFIG. 19). The cutter10is a rotatable tool formed by arranging a plurality of cutting tools in a circumferential direction. The cutter10is fitted to the cutting device (or another repair device) and used. At Step ST4, first, the cutting device mounted with the cutter10is transported into the nozzle120by the device-transporting jig, and is installed near the welded part X of the nozzle120. After centering is performed with respect to the inner periphery of the nozzle120, the cutting device is fixedly installed. The cutting device is then positioned with respect to the cracked portion in the welded part X based on the inspection data acquired at Step ST3(and punching). Subsequently, local cutting is performed. In the local cutting, the cutter10is applied to the cracked portion in the welded part X and rotated, thereby performing local cutting of the welded part X (for example, cutting to a depth up to 49 [mm]). Thereafter, the cutting device is transported out of the nozzle120and then recovered.

When the local cutting (Step ST4) is performed, a well deposit is produced as well for filling a locally cut portion.

Next, entire perimeter cutting is performed (entire-perimeter cutting step ST5). The entire perimeter cutting is for cutting a certain area including the welded part X to a certain depth over the entire perimeter of the inner periphery of the nozzle120. At Step ST5, cutting of the welded part X as a target to be repaired is performed prior to welding described later. First, the cutting device is transported in by the device-transporting jig and installed near the welded part X of the nozzle120. Centering of the cutting device is then performed with respect to the inner periphery of the nozzle120and fixedly installed. The cutting device is then positioned with respect to the welded part X in an axial direction of the nozzle120based on the inspection data acquired at Step ST3(and punching). Subsequently, entire perimeter cutting is performed with respect to a certain area including the welded part X. Thereafter, the cutting device is transported out of the nozzle120and then recovered. In the present embodiment, the cutting device performs entire perimeter cutting by using the cutting tools for cutting. A specific configuration of the cutting device and a specific content of the entire perimeter cutting are explained later in detail.

Next, welding is performed (welding step ST6). The welding produces a weld deposit in an area having already subjected to the entire perimeter cutting (Step ST5). At Step ST6, first, the welding device is transported in by the device-transporting jig and installed near the welded part X of the nozzle120. Centering and positioning of the welding device are then performed. Subsequently, the welding device produces a weld deposit in a locally cut portion (Step ST4). The welding device welds the area having already subjected to the entire perimeter cutting (Step ST5) throughout the area. Thereafter, the welding device is transported out of the nozzle120and then recovered.

Next, finish cutting is performed (finish cutting step ST7). The finish cutting is for performing finish cutting to an area already welded (Step ST6). At Step ST7, first, the cutting device is transported in by the device-transporting jig and installed near the welded part X of the nozzle120. Centering and positioning of the cutting device are then performed. Subsequently, the cutting device performs finish cutting to the area already welded (Step ST6). The finish cutting is performed in the same manner as in the entire perimeter cutting (Step ST5). In the present embodiment, the cutting device also serves as the buff device as described later. Therefore, the cutting device (the repair device) is not recovered from the nozzle120, and directly performs the next step ST8.

Next, buffing is performed (buffing step ST8). This buffing is for performing buffing to the area having subjected to the finish cutting (Step ST7), and an object thereof is to reduce a residual stress in the welded part X. At Step ST8, because the cutting device also serves as the buff device as described later, an installation step, a centering step, and a positioning step of the buff device are omitted. The buff device then performs buffing to the area having subjected to the finish cutting (Step ST7). Thereafter, the buff device (also serves as the cutting device) is transported out of the nozzle120and then recovered.

In a general reactor containment100, the containment main body110has a plurality of nozzles120(seeFIG. 18). Therefore, in the welded parts X of these nozzles120, a series of steps of from Step ST3to Step ST8are performed respectively. In the present embodiment, a repair device1described later includes a clamp mechanism3, and thus the repair device1is installed in the nozzle120in a self-standing manner. With this configuration, a plurality of repair devices1are respectively installed in each of the nozzles120, so that a repairing operation is performed for each of the nozzles120independently from each other. Accordingly, the repairing operation is performed efficiently. This feature is explained later.

Next, the device-transporting jig is hoisted and recovered from the work table140to outside of the containment main body110(Step ST9). Thereafter, the shield150is removed from the nozzle120, and the work table140is removed (Step ST10). Accordingly, a repairing operation of the welded part X is complete.

[Repair Device of Reactor Containment]

FIG. 1is a perspective view of the repair device according to the embodiment of the present invention.FIG. 2is an axial sectional view of the repair device shown inFIG. 1.FIGS. 3 to 5are respectively a plan view (FIG. 3), a front view (FIG. 4), and a side view (FIG. 5) of a turn table of the repair device shown inFIG. 1.

The repair device1repairs a welded part on the inner peripheral side of a pipe, and is used for a repairing operation of, for example, the welded part X between the nozzle120and the pipe130of the reactor containment100on the inner peripheral side thereof (seeFIG. 1). The repair device1includes a drive mechanism2, the clamp mechanism3, a cutting mechanism4, a buff mechanism5, an advancing and retracting mechanism6, a laser sensor81, and an image sensor82. Therefore, the repair device1includes both functions of a cutting device and a buff device, and can perform entire perimeter cutting (Step ST5), finish cutting (Step ST7), and buffing (Step ST8).

The drive mechanism2includes a casing21, a slide shaft22, a rotating shaft23, a turn table24, a slide shaft actuator25, and a rotating shaft actuator26(seeFIGS. 1 and 2).

The casing21is made of a substantially cylindrical member. Centering and positioning of the casing21are performed with respect to the inner wall surface of the nozzle120, thereby performing centering and positioning of the repair device1.

The slide shaft22is slid and displaced in an axial direction (a Y direction) with respect to the casing21, and has a hollow structure. The slide shaft22is inserted into the casing21, and is connected to the casing21via the slide shaft actuator25in the casing21. The slide shaft actuator25has a slider mechanism. The slide shaft actuator25is constituted by a guide rail251laid on an outer periphery of the slide shaft22, a slider252fixedly installed on the inner periphery of the casing21, and a servomotor (not shown) that drives the slider252. The slide shaft22is driven by the slide shaft actuator25, and is slid and displaced in the axial direction with respect to the casing21. The servomotor is connected to a controller in a monitoring center and drive-controlled. For example, the slide shaft22has a stroke of 200 [mm], and can be slid and displaced in a speed range of 0 [mm/s] to 2 [mm/s].

The rotating shaft23is rotationally displaced about the slide shaft22(in a θ1direction). The rotating shaft23is inserted into a hollow part of the slide shaft22, and is rotatably supported by a pair of bearings221,221in the slide shaft22. The rotating shaft23includes a flange231at one end thereof, and is connected to the rotating shaft actuator26on an outer periphery of the flange231. For example, the rotating shaft actuator26is a servomotor, and is installed on a side of the slide shaft22. In the present embodiment, a flange222is formed at one end of the slide shaft22, and the rotating shaft actuator26is fitted to the flange222. The rotating shaft23is driven by the rotating shaft actuator26, and is rotationally displaced about the slide shaft22. The rotating shaft actuator26is connected to the controller in the monitoring center and drive-controlled. For example, the rotating shaft23can be rotationally displaced in a rotational speed range of 0 [rpm] to 14 [rpm].

The turn table24is a rotating table for installing the cutting mechanism4, the buff mechanism5, and the advancing and retracting mechanism6thereon. The turn table24is fixedly installed to the flange231of the rotating shaft23and rotates together with the rotating shaft23. For example, in the present embodiment, the turn table24has a circular table shape, and a leg thereof is fixedly installed to the flange231, with a table surface thereof being directed to the axial direction of the rotating shaft23. For example, the turn table24rotates at a constant speed together with the rotating shaft23.

The clamp mechanism3clamps the inner wall surface of the nozzle120to fix the casing21inside the nozzle120(seeFIG. 1). A plurality of clamp mechanisms3are installed as a set on the outer periphery of the casing21. For example, in the present embodiment, four clamp mechanisms3at opposite ends of the casing21, in total, eight clamp mechanisms3are arranged with a gap of about 90 degrees. For example, the clamp mechanism3is formed by connecting a hydraulic cylinder31and a clamp33via a linking unit32(seeFIG. 1). In the clamp mechanism3, when the cylinder31is driven by remote control, the clamp33is driven via the linking unit32and displaced in a radial direction of the casing21. The clamp33is pressed against the inner wall surface of the nozzle120to clamp the inner wall surface, thereby fixing the casing21in the nozzle120. Because the clamp mechanisms3are driven by remote control to adjust an amount of displacement of the clamp33reciprocally, a position of the casing21with respect to the inner periphery of the nozzle120is adjusted. Accordingly, a centering operation of the repair device1(the casing21) is performed. The cylinder31of the clamp mechanism3is connected to the controller in the monitoring center and drive-controlled.

The cutting mechanism4performs cutting (entire perimeter cutting) over the entire inner periphery of the nozzle120(seeFIG. 1andFIGS. 3 to 5). The cutting mechanism4includes a cutting tool41for cutting. The cutting mechanism4is fitted to the advancing and retracting mechanism6described later, and installed near an edge on the turn table24. In the cutting mechanism4, when the turn table24is rotated, the cutting tool41turns about an axis of rotation (in the θ1direction) of the turn table24to cut the inner periphery of the nozzle120(rotational cutting). At this time, the cutting mechanism4is driven by the advancing and retracting mechanism6and slid and displaced in a predetermined direction (an R direction) on the turn table24, thereby changing a cutting depth thereof. An operation of the cutting mechanism4is explained later in detail.

The buff mechanism5performs buffing with respect to the welded part X of the nozzle120(seeFIG. 1andFIGS. 3 to 5). The buff mechanism5includes a buff51and a drive part52for rotating the buff51. Furthermore, the buff mechanism5is fitted to the advancing and retracting mechanism6described later and installed near the edge on the turn table24. The buff mechanism5performs buffing of the inner periphery of the nozzle120by rotating (spinning) the buff51and pressing the buff51against the inner periphery of the nozzle120. The turn table24rotates while the buff51is rotating, thereby moving (revolving) the position of the buff mechanism5about the axis of rotation (in the θ1direction) of the turn table24, to perform buffing with respect to the entire perimeter of the inner periphery of the nozzle120. The drive part52of the buff mechanism5is connected to the controller in the monitoring center and drive-controlled. An operation of the buff mechanism5is explained later together with the operation of the cutting mechanism4.

The advancing and retracting mechanism6causes the cutting mechanism4and the buff mechanism5to be displaced forward and backward on the turn table24(seeFIG. 1andFIGS. 3 to 5). For example, in the present embodiment, the advancing and retracting mechanism6is a slide mechanism, and is constituted by a rail61laid on the upper surface of the turn table24and extending in the radial direction (the R direction) of the turn table24, a long slider62that is slid and displaced along the rail61, and a servomotor (not shown) that drives the slider62. The advancing and retracting mechanism6holds the cutting mechanism4and the buff mechanism5at the opposite ends of the slider62. Accordingly, when the advancing and retracting mechanism6causes the slider62to move in one direction, the cutting tool41of the cutting mechanism4protrudes from the turn table24or the buff51of the buff mechanism5protrudes from the turn table24, thereby switching the cutting mechanism4and the buff mechanism5. Further, the advancing and retracting mechanism6adjusts the amount of displacement of the slider62in the R direction, thereby enabling to adjust a protruding amount of the cutting tool41and the buff51from the turn table24. The servomotor of the advancing and retracting mechanism6is connected to the controller in the monitoring center and drive-controlled. For example, the advancing and retracting mechanism6has a stroke of 85 [mm], and can be displaced forward and backward in a speed range of 0 [mm/s] to 15 [mm/s].

The laser sensor81measures an inner peripheral shape of the nozzle120(seeFIG. 1andFIGS. 3 to 5). The laser sensor81is installed near the edge of the turn table24, with an irradiation direction of the laser being directed radially outward of the turn table24. Accordingly, when the turn table24rotates, the position of the laser sensor81is moved about the axis of rotation of the turn table24. With this configuration, the laser sensor81can measure the inner peripheral shape of the nozzle120over the entire perimeter. The laser sensor81is data-communicably connected to the controller in the monitoring center, and transmits an output signal to the controller.

For example, the image sensor82is a CCD (Charge Coupled Device) camera (seeFIG. 1andFIGS. 3 to 5). For example, the image sensor82is installed on a camera stand (not shown) on the turn table24. The image sensor82can move an imaging direction thereof in a circumferential direction of the turn table24. Accordingly, the image sensor82can capture images of a cutting position of the cutting mechanism4, a buffing position of the buff mechanism5, a state inside the nozzle120and the like from above of the table surface. The image sensor82is connected to a monitor in the monitoring center.

A balancing mechanism91is arranged on the turn table24(seeFIGS. 3 and 4). When the cutting mechanism4and the buff mechanism5are displaced by driving the advancing and retracting mechanism6, the balancing mechanism91suppresses deflection or backlash of the advancing and retracting mechanism6due to an external force to maintain accuracy in a cutting depth at the time of cutting. For example, the balancing mechanism91includes an oil hydraulic cylinder, and an oil-circulation flow channel that connects front and rear chambers of the oil hydraulic cylinder via an orifice.

A distribution box92and an air nozzle93are also arranged on the turn table24(seeFIGS. 3 to 5). The distribution box92accommodates a distribution system for the cutting mechanism4, the buff mechanism5, the advancing and retracting mechanism6, and the balancing mechanism91. The air nozzle93injects air and has a function of blowing off cut chips generated in a cutting process, for example. The air nozzle93is installed respectively on a side of the cutting mechanism4and on a side of the buff mechanism5. Cut chips generated at the time of a repairing operation are sucked by a vacuum pipe (not shown) and then recovered at outside of the nozzle120.

Furthermore, the rotating shaft23has a hollow structure, and a slip ring27is arranged therein (seeFIG. 2). The slip ring27accommodates wiring (such as electric wiring and signal wiring) to the cutting mechanism4, the buff mechanism5, and the advancing and retracting mechanism6. The cutting mechanism4, the buff mechanism5, and the advancing and retracting mechanism6are connected to the controller in the monitoring center via such wiring and then drive-controlled.

Further, the rotating shaft23includes a plurality of swivel joints28at an end opposite to the flange222(an end positioned on a side of the containment main body110in a state where the repair device1is installed) (seeFIG. 2). These swivel joints28become a channel for supplying working fluid for the cutting mechanism4, the buff mechanism5, the advancing and retracting mechanism6, the balancing mechanism91, and the air nozzle93.

[Cutting Performed by Repair Device]

FIGS. 6 to 9are respectively a flowchart (FIG. 6) of an entire-perimeter cutting process performed by the repair device shown inFIG. 1and explanatory diagrams thereof (FIGS. 7 to 9). Among these drawings,FIG. 7depicts a state where the repair device1is installed in the nozzle120, andFIGS. 8 and 9depict a state of cutting the welded part X.

As mentioned above, the repair device1includes both functions of the cutting mechanism and the buff mechanism5, and can respectively perform the entire perimeter cutting (Step ST5), the finish cutting (Step ST7), and the buffing (Step ST8). As an example, a case where the repair device1is used as the cutting device to perform the entire perimeter cutting (Step ST5) is explained (seeFIG. 6).

At the entire perimeter cutting (Step ST5), the repair device1is transported in (Step ST51) (seeFIG. 7). Specifically, the repair device1is inserted from the opening141of the work table140into the nozzle120and installed near the welded part X.

At this time, the clamp mechanism3clamps the inner periphery of the nozzle120to fix the repair device1(seeFIG. 7). Therefore, the repair device1is installed in the nozzle120in a self-standing manner without any assistance from a side of the work table140. Accordingly, a plurality of repair devices1can be arranged, respectively, in a plurality of nozzles120and operated independently from each other, thereby enabling to streamline a repairing operation. Because conventional repair devices cannot be installed in the nozzle in a self-standing manner, assistance such as supporting a rear part of the repair device from the side of the work table is required. Therefore, the work table is occupied for assisting one repair device, and thus there is a problem that repairing operations for a plurality of nozzles cannot be performed simultaneously.

Next, centering of the repair device1is performed (centering step ST52). At Step ST52, it is set such that the eight clamp mechanisms3reciprocally adjust the clamp height of the clamps33so that the shaft of the casing21and the shaft of the nozzle120substantially coincide with each other. Specifically, it is set so that the shaft of the slide shaft22(a Y direction) and the shaft of the nozzle120coincide with each other. The respective clamp mechanisms3fix the clamps33, and the repair device1is fixedly installed in a state where centering of the repair device1is performed with respect to the nozzle120.

Next, positioning of the cutting mechanism4is performed (positioning step ST53). At Step ST53, a positional relation between the cutting mechanism4and the welded part X in the axial direction of the nozzle120is set based on the inspection data acquired at Step ST3(and punching). Specifically, the slide shaft22slides in the axial direction (the Y direction) and the turn table24moves in the axial direction of the nozzle120. With this configuration, it is set so that the position of the cutting mechanism4on the turn table24and the position of the welded part X achieve a predetermined positional relation in the axial direction of the nozzle120. At this time, image data from the image sensor82is transmitted to the controller, and the positional relation between the cutting mechanism4and the welded part X is adjusted, while confirming the image data by a monitor of the controller.

Next, the inner peripheral, shape of the nozzle120is measured (inner-peripheral shape measuring step ST54). At Step ST54, the turn table24goes around in the θ1direction, and the laser sensor81measures the inner peripheral shape of the nozzle120. In this measurement, measurement data of at least the opposite ends of an area to be cut (an area subjected to cutting) is respectively acquired. Specifically, the slide shaft22is displaced in the Y direction to move a measurement position of the laser sensor81, thereby acquiring the measurement data at the opposite ends of the area to be cut. The inner peripheral shape of the nozzle120in the entire area to be cut is estimated based on the measurement data. The area to be cut is a certain area including the welded part X, and a range in the Y direction is set based on the inspection data acquired at Step ST3.

Next, the repair device performs the entire perimeter cutting with respect to the area to be cut (entire-perimeter cutting step ST55). At Step ST55, the turn table24is rotated at a predetermined speed. At this time, the rotational speed of the turn table24is controlled so that an end of the cutting tool41turns at a set speed. The advancing and retracting mechanism6then moves the cutting mechanism4in the radial direction (the R direction) of the turn table24, and brings the cutting tool41of the cutting mechanism4into contact with the inner wall surface of the nozzle120. The cutting tool41then turns in the θ1direction due to the rotations of the turn table24, to cut the inner periphery of the nozzle120(seeFIG. 8). Furthermore, the slide shaft22is gradually slid and displaced at a certain speed in the axial direction (the Y direction), so that the cutting tool41helically turns with a narrow pitch, thereby cutting the inner wall surface of the nozzle120in a cylindrical shape (entire perimeter cutting). At this time, the advancing and retracting mechanism6is driven and displaced forward and backward in a direction of the inner wall surface of the nozzle120(in the R direction). Accordingly, the turning radius of the cutting tool41is enlarged or contracted to adjust a cutting depth h (seeFIG. 9). The cutting tool41can turn in a speed range of 0 [m/min] to 30 [m/min] to perform cutting by rotationally displacing the rotating shaft23in the rotational speed range of 0 [rpm] to 14 [rpm].

The inner peripheral shape of the nozzle120is not necessarily a true circle and, for example, the inner peripheral shape can be elliptical, or can include irregularities, or a bend on the inner wall surface at a weld line. Furthermore, a shaft of the repair device and the shaft of the nozzle120may be out of alignment. Therefore, at Step ST55, a turning trajectory of the cutting tool41is calculated and controlled so that the inner periphery of the nozzle120is cut to a certain cutting depth h. Specifically, the turning trajectory of the cutting tool41in the area to be cut is calculated based on a relation between the measurement data (Step ST54) of the inner peripheral shape of the nozzle120in the area to be cut and the predetermined cutting depth h. Further, a relation among the rotational speed of the turn table24in the θ1direction, the sliding speed of the slide shaft22in the Y direction, and forward and backward displacement of the advancing and retracting mechanism6in the R direction is calculated based on the calculation result. The slide shaft22and the advancing and retracting mechanism6are driven based on the calculation result, to perform the entire perimeter cutting (profile copy cutting). Accordingly, the area to be cut is uniformly cut to the predetermined cutting depth h over the entire perimeter of the inner periphery of the nozzle120.

Next, the cutting mechanism4and the slide shaft22are returned to initial positions, and thereafter the repair device1is transported out of the nozzle120and then recovered (Step ST56). With this process, the entire perimeter cutting step ST5is complete.

While the entire perimeter cutting (Step ST5) has been explained as an example, the finish cutting (Step ST7) is performed in a similar manner (not shown). That is, the relation among the rotational speed of the turn table24in the θ1direction, the sliding speed of the slide shaft22in the Y direction, and the forward and backward displacement of the advancing and retracting mechanism6in the R direction is calculated based on the relation between the measurement data of the inner peripheral shape of the nozzle120in the area to be cut (Step ST54) and the predetermined cutting depth h. The turn table24, the slide shaft22, and the advancing and retracting mechanism6are driven based on the calculation result, thereby controlling the turning trajectory of the cutting tool41in the area to be cut. Accordingly, the area to be cut is uniformly cut to the predetermined cutting depth h, and the finish cutting is appropriately performed.

Furthermore, the buffing (Step ST8) is also performed in a similar manner (not shown). That is, the relation among the rotational speed of the turn table24in the θ1direction, the sliding speed of the slide shaft22in the Y direction, and the forward and backward displacement of the advancing and retracting mechanism6in the R direction is calculated based on the relation between the measurement data (Step ST54) of the inner peripheral shape of the nozzle120in an area to be buffed (same as the area to be cut) and a pressing force of the buff51against the inner wall surface of the nozzle120. The buff51helically revolves, while rotating at a predetermined rotational speed, to perform appropriate buffing. At this time, the buff51buffs the area to be buffed at an appropriate moving speed by controlling the rotational speed of the turn table24and the sliding speed of the slide shaft22. Further, the buff51buffs the area to be buffed with an appropriate pressing force, by controlling the forward and backward displacement of the advancing and retracting mechanism6. Accordingly, the area to be buffed is appropriately buffed.

[Cutting-Tool Switching Unit of Cutting Mechanism]

FIG. 10is a plan view of a cutting mechanism of the repair device shown inFIG. 1.FIG. 11andFIG. 12are respectively a sectional view as viewed from an arrow B (FIG. 11), and a sectional view as viewed from an arrow. C (FIG. 12), of the cutting mechanism shown inFIG. 10.FIGS. 13 to 16are explanatory diagrams of a function of the cutting mechanism shown inFIG. 10.

In the repair device1, the cutting mechanism4includes a structure capable of switching the cutting tools41. A configuration of the cutting mechanism4is explained below.

The cutting mechanism4includes a plurality of cutting tools41, a cutting-tool switching unit42, and a cutting tool table43(seeFIG. 10). The cutting tools41are tool bits for cutting, and can be constituted by the same type or different types. For example, in the present embodiment, at the entire-perimeter cutting step ST5, because the cutting tools41are sequentially changed and used, five cutting tools41of the same type are used. The cutting-tool switching unit42is a drive mechanism that holds the cutting tools41and moves and switches these cutting tools41. The cutting-tool switching unit42is explained later in detail. The cutting tool table43is a member that fixes the cutting mechanism4to the slider62of the advancing and retracting mechanism6. For example, in the present embodiment, the cutting tool table43supports the cutting-tool switching unit42, and is fixed to the slider62of the advancing and retracting mechanism6. With this configuration, the cutting mechanism4and the slider62of the advancing and retracting mechanism6are integrated.

The cutting-tool switching unit42includes a switching-unit main body421, a cutting-tool support body422, a fitted rotating shaft423, a pinion424, a rack425, a cylinder426, a piston427, a first positioning pin428, and a second positioning pin429(seeFIG. 11).

The switching-unit main body421is a casing having a substantially cylindrical container shape. The cutting-tool support body422holds the cutting tools41. The cutting-tool support body422has a substantially disk-like shape, and holds the five cutting tools41with an equal gap on an outer peripheral edge on the upper surface side thereof. The fitted rotating shaft423is a rotating shaft of the cutting-tool support body422. The cutting-tool support body422and an internal mechanism of the switching-unit main body421are connected to each other via the fitted rotating shaft423. An upper surface of the switching-unit main body421and a lower surface of the cutting-tool support body422are made to abut on each other, and the fitted rotating shaft423is inserted into the cutting-tool support body422from the upper surface of the cutting-tool support body422. The fitted rotating shaft423and the cutting-tool support body422are coupled by a bolt and integrated on the upper surface of the cutting-tool support body422. A flange4231is formed on the fitted rotating shaft423.

The pinion424is rotatably fitted to and installed on the fitted rotating shaft423, with one surface of the pinion424abutting on the flange4231of the fitted rotating shaft423. The rack425is inserted into and slidably arranged in the cylinder426in the switching-unit main body421. The pinion424and the rack425constitute a rack/pinion mechanism424,245. The cylinder426is buried in the switching-unit main body421. The piston427is a member that presses the rack425in an axial direction. The piston427is connected to an end of the rack425, and is inserted into and arranged in the cylinder426together with the rack425. When a fluid pressure such as an air pressure is applied from behind, the piston427presses the rack425in an axial direction at the front by the fluid pressure. The fluid pressure to be applied to the piston427is supplied from outside of the repair device1to the cutting mechanism4via the swivel joints28and the rotating shaft23(seeFIG. 2).

The first positioning pin428controls a positional relation between the switching-unit main body421and the cutting-tool support body422(seeFIGS. 11 and 13). A ratchet groove4212is formed on the upper surface of the switching-unit main body421, and a pin hole4221is formed on the lower surface of the cutting-tool support body422. The first positioning pin428is inserted into the pin hole4221in the cutting-tool support body422, and an apex thereof is arranged, engaged with the ratchet groove4212on the switching-unit main body421. The first positioning pin428biases the apex thereof into engagement with the ratchet groove4212by a spring force. Accordingly, the first positioning pin428and the ratchet groove4212engages with each other to constitute a first ratchet mechanism428,4212.

The second positioning pin429controls a positional relation between the flange4231of the fitted rotating shaft423and the pinion424of the rack/pinion mechanism424,245(seeFIGS. 11 and 14). A ratchet groove4241is formed on an upper surface of the pinion424, and a pin hole4232is formed on a lower surface of the flange4231. The second positioning pin429is inserted into the pin hole4232in the flange4231, and an apex thereof is arranged, engaged with the ratchet groove4241on the pinion424. The second positioning pin429biases the apex thereof into engagement with the ratchet groove4241by a spring force. Accordingly, the second positioning pin429and the ratchet groove4241engages with each other to constitute a second ratchet mechanism429,4241.

When the pinion424rotates in a forward direction, the second ratchet mechanism429,4241is separated to rotate only the pinion424. When the pinion424rotates in an opposite direction, the second ratchet mechanism429,4241engages to connect the pinion424to the flange4231. In this example, when the piston427is driven in the forward direction to rotate the pinion424, the pinion424rotates in the opposite direction. Accordingly, the second ratchet mechanism429,4241engages, and the pinion424and the flange4231rotate together. On the other hand, when the piston427is driven in the opposite direction to rotate the pinion424, the pinion424rotates in the forward direction. Accordingly, the second ratchet mechanism429,4241is separated and only the pinion424rotates.

Furthermore, the first ratchet mechanism428,4212, and the second ratchet mechanism429,4241are respectively formed, corresponding to the arrangement of the five cutting tools41held by the cutting-tool support body422(seeFIG. 15).

In the cutting mechanism4, switching of the cutting tools41is performed as described below.

In a fixed state of the cutting tools41, a fluid pressure (for example, a hydraulic pressure) is applied to a predetermined position in the switching-unit main body421. For example, in the present embodiment, the fluid pressure is applied to a narrow gap (not shown) between the flange fixed to the fitted rotating shaft423and an inner wall surface of the switching-unit main body421. Alternatively, the fluid pressure can be applied to a narrow gap (not shown) on a bonded surface between the flange fixed to the fitted rotating shaft423and the flange fixed in the switching-unit main body421. The fitted rotating shaft423is then pressed against the switching-unit main body421due to the fluid pressure and fixed. Because the cutting-tool support body422is fixed on the fitted rotating shaft423, the cutting-tool support body422is fixed with respect to the switching-unit main body421. With this configuration, the cutting-tool switching unit42is fixed with respect to an external force and an internal rotation force, and the cutting tools41become fixed. In this state, the fluid pressure is not applied to the piston427.

At the time of switching the cutting tools41, the hydraulic pressure (a hydraulic pressure applied to a predetermined position in the switching-unit main body421) for fixing the cutting tools41(the cutting-tool switching unit42) is released. Accordingly, the cutting-tool switching unit42can rotate freely, thereby enabling to switch the cutting tools41. Subsequently, the fluid pressure is applied to the piston427(seeFIG. 12). Supply of the air pressure to the first positioning pin428and the second positioning pin429is stopped, and a locked state of the first ratchet mechanism428,4212and the second ratchet mechanism429,4241is released. When the piston427is driven in the forward direction due to the fluid pressure, the rack425is pressed and moved deep into the cylinder426(by a shift amount when one cutting tool41is shifted). The pinion424rotates due to an engagement with the rack425. In this state, the pinion424rotates in the opposite direction. Accordingly, the second ratchet mechanism429,4241engages, and the pinion424and the flange4231rotate together. The fitted rotating shaft423then rotates together with the flange4231, and the cutting-tool support body422rotates together with the fitted rotating shaft423(seeFIG. 11). The rotation direction thereof becomes the forward direction with respect to the first ratchet mechanism428,4212. Therefore, the cutting-tool support body422rotates with respect to the switching-unit main body421, and the cutting tools41are rotated by one cutting tool. With this process, switching of the cutting tools41is performed.

The piston427returns to the original position due to releasing of a fluid pressure. The piston427is then driven in the opposite direction, and the rack425is returned. The pinion424is then rotated due to the engagement with the rack425. In this state, the pinion424is rotated in the opposite direction. Accordingly, the second ratchet mechanism429,4241is separated, and only the pinion424rotates. Therefore, the cutting tool41remains in a fixed state because the flange4231(the fitted rotating shaft423) does not rotate.

Furthermore, switching of the cutting tools41is performed at the time of a cutting operation (Steps ST5and ST7). For example, in the repair of the nozzle120, because the area to be cut may be wide, all areas to be cut may not be cut only by a single cutting tool41. Therefore, the cutting mechanism4includes the cutting-tool switching unit42and performs cutting while replacing the cutting tools41by the cutting-tool switching unit42, thereby enabling to continue the cutting operation, with the repair device1being installed in the nozzle120. Accordingly, a repairing operation is streamlined.

As explained above, the repair device1includes the casing21, the slide shaft22slidably arranged with respect to the casing21, the turn table24rotatably arranged with respect to the slide shaft22, the cutting mechanism4installed on the turn table24and including the cutting tools41, and the advancing and retracting mechanism6that displaces a radius of rotation of the cutting tools41with respect to the rotations of the turn table24forward and backward by displacing the cutting mechanism4forward and backward (seeFIGS. 1 to 5). Furthermore, in a state where the casing21is centered and positioned with respect to the pipe (the nozzle120), the turn table24is rotationally displaced while the slide shaft22slides in an axial direction, and the advancing and retracting mechanism6displaces the cutting mechanism4forward and backward. Accordingly, the cutting tools41helically turn along the inner peripheral shape of the pipe to cut the inner periphery of the pipe (seeFIGS. 6 to 9). In such a configuration, rotational cutting by the cutting tools41is realized by an interaction among sliding displacement of the slide shaft22, rotational displacement of the turn table24, and a speed of forward and backward displacement of the buff mechanism5. Thereby, the area to be cut having a substantially cylindrical shape can be cut smoothly, thereby improving cutting accuracy. Accordingly, any aftertreatment is not required, and a repairing operation can be streamlined. For example, in a configuration in which a cutting mechanism helically revolves to perform cutting, while rotating a cutting tool (see Patent Literature 1), aftertreatment becomes necessary due to a step generated in a cutting trace.

Furthermore, the repair device1includes a measuring unit (the laser sensor81) that acquires measurement data of the inner peripheral shape of the pipe (seeFIG. 1andFIGS. 3 to 5). The relation among the sliding speed of the slide shaft22, the rotational speed of the turn table24, and forward and backward displacement of the cutting mechanism4is calculated based on the relation between the acquired measurement data and the predetermined cutting depth h, to control the turning trajectory of the cutting tool41(see Steps ST54and ST55inFIG. 6). In such a configuration, the area to be cut can be cut along the inner peripheral shape of the pipe (profile copy rotational cutting). Accordingly, the area to be cut having a non-uniform shape can be cut accurately. In such a configuration, the turning trajectory of the cutting tool41can be finely adjusted, thereby enabling to simplify a centering operation of the repair device1with respect to the nozzle120(Step ST42). That is, when the repair device1is to be installed in the nozzle120, centering needs only to be performed in such a degree that an axis of the slide shaft22(the Y direction) and an axis of the nozzle120substantially agree with each other, and the positional relation between an outer peripheral edge of the turn table24and the inner periphery of the nozzle120do not need to be strictly determined.

The repair device1includes the buff mechanism5having the buff51for buffing (seeFIG. 1andFIGS. 3 to 5). The buff mechanism5and the cutting mechanism4are installed so as to be changed by the turn table24. In such a configuration, because the repair device1serves as the buff mechanism5and the cutting mechanism4, there is an advantage in that operations related to transporting in/out and installation of the device can be omitted, as compared to a configuration in which the buff mechanism and the cutting mechanism are separately used.

In the repair device1, the advancing and retracting mechanism6displaces the turning radius of the buff mechanism5with respect to the rotations of the turn table24forward and backward by forward and backward displacement of the buff mechanism5made by the advancing and retracting mechanism6(seeFIG. 1andFIGS. 3 to 5). In such a configuration, buffing can be performed by revolving the buff51helically while in rotation, by an interaction among sliding displacement of the slide shaft22, rotational displacement of the turn table24, and forward and backward displacement of the buff mechanism5. With this configuration, buffing can be smoothly performed with respect to the area to be buffed having a substantially cylindrical shape. Particularly, by controlling the turning trajectory of the buff51based on the relation between the measurement data (Step ST54) of the inner peripheral shape of the pipe in the area to be buffed and the pressing force of the buff51against the inner periphery of the pipe, buffing can be appropriately performed with respect to the area to be buffed with a predetermined pressing force and a predetermined moving speed.

The repair device1includes the clamp mechanism3that holds the casing21in a state where the casing21is positioned in the pipe (seeFIGS. 1 and 7). In such a configuration, because the clamp mechanism3appropriately holds the position of the casing21(particularly, a relative position of the repair device in an axial direction of the pipe with respect to a target to be cut) at the time of controlling the turning trajectory of the cutting tool41, the repair device1is installed in the pipe in a self-standing manner. With this configuration, because each of the repair devices1can be arranged in a plurality of pipes and individually operated, a repairing operation can be streamlined.

This repair method includes the inner-peripheral shape measuring step (Step ST54) of acquiring the measurement data of the inner peripheral shape of the pipe, and the cutting step (Step ST55) at which profile copy cutting is performed with respect to the inner periphery of the pipe, while the cutting tool41is being turned helically along the inner peripheral shape of the pipe (seeFIGS. 6 to 9). In such a configuration, because cutting (profile copy rotational cutting) can be performed with respect to the area to be cut along the inner peripheral shape of the pipe, the area to be cut having a non-uniform shape can be cut accurately. Accordingly, any aftertreatment is not required, and thus a repairing operation can be streamlined.

The repair device1includes the casing21, the slide shaft22slidably arranged with respect to the casing21, the turn table24rotatably arranged with respect to the slide shaft22, and the cutting mechanism4installed on the turn table24and including the cutting tools41(seeFIGS. 1 to 5). Furthermore, the turn table24is rotationally displaced while the slide shaft22slides in an axial direction, so that the cutting tools41helically turn to cut the inner periphery of the pipe (the nozzle120) (seeFIGS. 6 to 9). Further, the cutting mechanism4includes the cutting-tool switching unit42that switches the cutting tools41(seeFIGS. 10 to 12). In such a configuration, the cutting tools41helically turn to cut the inner periphery. Therefore, when the area to be cut is wide, the cutting tools41need to be replaced. At this time, the cutting mechanism4performs cutting while replacing the cutting tools41by the cutting-tool switching unit42, thereby enabling to continue a cutting operation, with the repair device1being installed in the pipe. Accordingly, a repairing operation can be streamlined.

In the repair device1, the cutting-tool switching unit42includes the switching-unit main body421installed on a side of the turn table24, the cutting-tool support body422that supports the plurality of cutting tools41and switches the cutting tools41by rotational displacement, the fitted rotating shaft423connected to the cutting-tool support body422, and the drive mechanism (the piston427) connected to the fitted rotating shaft423via the ratchet mechanism (the second ratchet mechanism429,4241) (seeFIGS. 11 and 12). In such a configuration, when the drive mechanism (the piston427) is driven in the predetermined forward direction, the ratchet mechanism (the second ratchet mechanism429,4241) engages to rotate the fitted rotating shaft423. Accordingly, the cutting-tool support body422rotates to switch the cutting tools41. On the other hand, when the drive mechanism (the piston427) is driven in the opposite direction, the ratchet mechanism (the second ratchet mechanism429,4241) restricts rotations of the fitted rotating shaft423. Accordingly, the drive mechanism (the piston427) returns to an initial position without switching the cutting tools41.

INDUSTRIAL APPLICABILITY

As described above, the repair device and the repair method according to the present invention are advantageous in a characteristic that a repairing operation can be streamlined.

REFERENCE SIGNS LIST