JP2007160406A - Cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutter which further reduce a work time in cutting work for piping laid out in a narrow area. <P>SOLUTION: In this cutter for cutting pipes 5, 6 disposed piercing a container 1, a cutting means body 13 includes: means 22, 23, 24 for positioning the cutting means body 13 along the sectional shapes of the pipes 5, 6 and moving the same; means 21a, 21b to 22 for holding and supporting the pipe to be cut; and means 14 to 17, 20 for feeding an electrode 18 to the pipes 5, 6 in cutting the pipes 5, 6 by discharge machining. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cutting device, and in particular, positioning, setting, etc., when cutting a pipe arranged through a container with work such as replacement or repair of equipment arranged in a narrow area The present invention relates to a cutting apparatus that can quickly and easily cut a pipe without requiring a long time.

  For example, in the case of a reactor pressure vessel applied to a nuclear power plant, piping or the like that is arranged to penetrate the vessel or to be arranged to penetrate the vessel through a nozzle formed in the vessel In order to secure a wider space inside the container, the piping inside the container is often bent and laid out in many cases.

  In such a piping layout, when cutting pipes due to equipment replacement or repair work, cutting from the outside of the container and drawing the remaining piping into the container, or a cutting device inside the pipe A method of cutting pipes by inserting a pipe was used.

  Also, when cutting a pipe that penetrates and connects to a pressure vessel, first discharge the coolant in the vessel to the outside, cut the pipe that is exposed to the space, and then attach a stopper to the cut portion. It was constructed and the process of filling the container with water again was performed.

  For example, Patent Literature 1 is disclosed as a technique for cutting a pipe located at a high place of a reactor pressure vessel.

In addition, the discharge electrode is often used for cutting the pipe, but the technique using this discharge electrode is applied as a repair to a narrow region of the reactor pressure vessel as seen in Patent Document 2, for example. In some cases.
Japanese Patent Publication No. 6-73771 JP 2002-168992 A

  As described above, when cutting a pipe that is placed in a pressure vessel and bent suddenly in the container, the coolant in the container is discharged to the outside, and the pipe that is exposed in the space is cut. After that, a stopper was installed at the cut part and the process of filling the container again with the coolant took a long time due to the large amount of coolant flow. Imposed a lot of labor on the workers.

  In addition, when the coolant was poured into and discharged from the pressure vessel repeatedly, an additional burden on the worker was added.

  In addition, the pipe cutting work laid out in the narrow area takes a long time, but the longer the time elapses, the more trouble the next process has.

  Therefore, when cutting a pipe laid out in a narrow area, further reduction in construction time has been demanded.

  The present invention has been made based on such a demand, and an object of the present invention is to provide a cutting device that further shortens the working time in cutting work of piping laid out in a narrow area.

  In order to achieve the above-described object, the cutting device according to the present invention cuts a pipe between the container inner wall and the pipe when the pipe is inserted and the pipe arranged along the container inner wall is cut. In the cutting apparatus for disposing the main body and cutting the pipe, the cutting means main body positions and moves the cutting means main body along the shape of the pipe, and means for gripping and supporting the pipe to be cut When the electric discharge machining is performed on the pipe that cuts from the electrode, a means for feeding the pipe toward the pipe that cuts the electrode is provided.

  When cutting a pipe laid out in a narrow area, the cutting apparatus according to the present invention sandwiches and supports means for positioning and moving the main body of the cutting apparatus along the shape of the pipe in the narrow area and the pipe to be cut When cutting by means of electric discharge machining from the electrode to the pipe, it has a means to feed the electrode toward the pipe, so that even a pipe laid out in a narrow area can be cut faster and more accurately. This can be done and the labor burden on the operator can be further reduced.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a cutting device according to the present invention will be described with reference to the drawings and reference numerals attached to the drawings.

  FIG. 1 is a partially cutaway conceptual view of a reactor pressure vessel when the cutting device according to the present invention is applied to a reactor pressure vessel as an example.

  The reactor pressure vessel generally indicated by reference numeral 1 is formed in a long cylindrical shape with an end plate disposed above.

  The reactor pressure vessel 1 formed in the shape of a long cylinder has a control rod drive mechanism 2 on the bottom side and nozzles 3a and 3b for supplying and discharging coolant at an intermediate portion. For example, taking a reactor recirculation system as an example, piping penetrates the reactor pressure vessel 1 through a nozzle 3a extending from a biological shielding wall 40 disposed in a reactor containment vessel (not shown). When entering the interior, it is configured to be bent suddenly through the elbow 5 and connected to a rising pipe 6 (specifically, a jet pump riser pipe or the like) 6.

  Many rising pipes 6 are provided along the wall surface of the reactor pressure vessel 1, and are supported on the wall surface by many mounting brackets 7.

  As described above, the wall surface of the reactor pressure vessel 1 is formed in a narrow area, in which many pipes such as the rising pipe 6, the mounting bracket 7, and the nozzles 3 a and 3 b are laid out.

  When the rising pipe 6 laid out in such a narrow region is cut by work such as repair, the cutting device 8 moves along the wall surface of the reactor pressure vessel 1 and is set at a predetermined position.

  The cutting device 8 is provided by using, for example, the operating floor 4 and is suspended by a hoist 10 attached to a gantry crane 9 that slides on a rail 9a, as well as an electrode drive cable 11 and an electric discharge machining power cable 12. Are connected to each of a control panel and a power panel (both not shown).

  On the other hand, the cutting device 8 set in the narrow portion between the reactor pressure vessel 1 and the rising pipe 6 is incorporated in the main body frame 13 and driven by the servo motor 14 as shown in FIGS. A ball screw 15 that is rotationally driven by force, a feed carriage 17 that moves forward and backward by the rotational drive of the ball screw 15 and slides on the linear bearing 16 during the forward and backward movement, and an electrode 18 that is disposed on the bottom side of the main body frame 13. I have.

  As shown in FIG. 3, the electrode 18 is made wider than the diameter of the tube cross section A to be cut, and is made of a material such as silver tungsten.

  However, as shown in FIG. 3, the electrode 18 has a shape in which the end portion of the electrode 18 is inclined, and is connected to the other inclined shape through the connection portion 19 so as to match each other. Specifically, the connecting portion 19 is coupled to the counterpart electrode 18 using a bolt.

  The connecting portion 19 of the electrode 18 is formed in an inclined shape. If the connecting portion 19 is made vertical, the electrode 18 cuts the tube cross section A in the vertical direction, and the electric discharge machining is performed in the gap portion of the connecting portion 19. This is for the purpose of preventing the occurrence of uncut parts.

  Further, the electrode 18 has a shape in which the width of both side portions is widened and the width of the intermediate portion is narrowed. In this way, the width of both side portions is widened and the width of the intermediate portion is narrowed for the following reason.

  That is, when the electrode 18 is moved in the vertical direction of the tube cross section A and cut into a guillotine by discharge from the electrode 18, the cutting length L per unit lateral width of the electrode 18 differs as shown in FIG. come. Here, FIG. 4 shows a ¼ section of the tube section A, but the cutting length L per unit width of the electrode 18 is a solid line with respect to this ¼ section. As shown, it is significantly longer at the side edges. For this reason, when one pipe is cut, the amount of consumption of the electrode 18 varies from place to place, and the consumable parts are concentrated on the place side end portion of the pipe, so a plurality of pipes are cut by one electrode 18. It becomes difficult.

  For this reason, the electrode 18 has a shape in which the width on both sides where the wear is severe is wide and the width of the intermediate portion is narrow.

  The electrodes 18 are arranged on the outer sides of both sides of the tube cross section A, and are supported and fixed by connecting rods 20 incorporated in the main body frame 13.

  Further, the feed carriage 17 including the connecting rod 20 that supports and fixes the electrode 18 moves forward and backward through the ball screw 15 and the linear bearing 16, and the electrode 18 also moves forward and backward along with this forward and backward movement, so that the tube cross section A is improved. It can be cut.

  Further, the feed carriage 17 includes a swing mechanism (not shown) that swings the connecting rod 20 finely, and shifts the contact position between the connecting portion 19 of the electrode 18 and the tube cross section A to prevent uncut portions. This facilitates the discharge of cutting powder (hereinafter referred to as swarf) generated during cutting.

  Further, as shown in FIG. 3, the cutting device 8 includes insulated clamps 21a and 21c, and holds and fixes the tube cross-section A so as to be sandwiched therebetween. Here, the clamp 21a is configured so that the air cylinder 22 can be switched between holding and non-holding the pipe cross section A.

  On the other hand, the other clamp 21 b is formed of a conductor at a contact portion with the pipe cross section A, and an insulating material is interposed between the conductor and the main body frame 13. Then, by applying a potential different from that of the electrode 18 to the conductor, discharge is easily generated between the tube cross section A and the electrode 18.

  Further, as shown by a two-dot chain line in FIG. 2, the cutting device 8 includes a fixed link air cylinder 22 and a pantograph (jack mechanism) 23 between the rising pipe 6 disposed on the back side of the main body frame 13. The fixed link 24 is provided and is positioned and moved with respect to the rising pipe 6 by the fixed link 24, while the main body frame 13 is fixedly supported to the standing pipe 6 during the cutting of the pipe cross section A, and after the cutting. The rising pipe 6 is separated from the reactor pressure vessel 1.

  Moreover, the cutting device 8 arranges the swarf recovery hose 26 and the swarf recovery nozzle 27 in the rising pipe 6 and sucks the generated swarf into the recovery hose 26 through the rising pipe 6 during the cutting of the pipe cross section A. A water stream with a reduced content is passed through the discharge surface so that good cutting can be performed continuously.

  Further, the cutting device 8 has an insulating plate 25 attached to the connecting rod 20 on the reactor pressure vessel 1 side, and the electrode 18 accidentally approaches the reactor pressure vessel 1 during the feeding operation of the electrode 18 to cause erroneous discharge and processing. I try not to let you.

  As described above, the present embodiment uses the gantry crane 9 and the hoist 10 under remote control and guides to the narrow region between the rising pipe 6 and the reactor pressure vessel 1. The cutting device 8 is positioned and fixedly supported by the fixed link 24, and the tube section A as a cutting object is fixedly clamped by the clamps 21a, 21b, and 21c, and the tube section A is cut by electric discharge machining of the electrode 18. Therefore, when cutting pipes, the drainage of coolant in the reactor pressure vessel, repeated injection of water, and construction work of stoppers at the pipe cutting part are not performed, and the labor burden on the operator is reduced. Can be further reduced.

  FIG. 5 is a front view showing a second embodiment of a cutting device according to the present invention applied to a reactor pressure vessel as an example.

  In addition, the same code | symbol is attached | subjected to the component same as the component of 1st Embodiment, and duplication description is abbreviate | omitted.

  The cutting device 8 according to the present embodiment adds the constituent elements shown in the first embodiment, and among these constituent elements, a thruster 28 including rotating blades 29 functioning as so-called screws on both sides of the main body frame 13; A thruster rotating motor 30 for driving the thruster 28 is provided, and a thrust (jet force) is generated by rotating the rotary blade 29 so that the main body frame 13 can be pressed against the inner wall side of the reactor pressure vessel. It is a thing.

  In addition, when the piping is cut, as long as all the coolant in the pressure vessel is not drained, swimming can be performed by the jet of the thruster 28, and the inside of the vessel can be moved.

  Further, the cutting device 8 according to the present embodiment is provided with traveling wheels 31 that can come into contact with the inner wall of the reactor pressure vessel 1 on both sides of the main body frame 13, and a motor 32 with a speed reducer that drives the traveling wheels 31. It is provided.

  As described above, in this embodiment, in addition to the components shown in the first embodiment, the thruster 28, the traveling wheel 31, the thruster rotating motor 30 that drives each of the thruster 28 and the traveling wheel 31, and the speed reducer. Since the attached motor 32 is provided, the cutting device 8 can be brought into contact with the inner wall of the reactor pressure vessel by the jet force of the thruster 28. It can be moved along the inner wall of the furnace pressure vessel 1, and the cutting device 8 can be freely moved even in a narrow region to facilitate and quickly cut the piping.

  FIG. 6 is a front view showing a third embodiment of a cutting device according to the present invention applied to a reactor pressure vessel as an example.

  In addition, the same code | symbol is attached | subjected to the component same as the component shown in 1st Embodiment and 2nd Embodiment, and duplication description is abbreviate | omitted.

  The cutting device 8 according to the present embodiment extends downward from the main body frame 13, for example, two fixed connecting rods 35 are arranged outside the tube cross section A, and an electrode 18 is provided at the lower end thereof. is there.

  Further, the cutting device 8 according to the present embodiment drives a plurality of thrusters 28 provided with a rotating blade 29 in the main body frame 13, a thruster rotating motor 30 and a traveling wheel 31 that drive these thrusters 28, and the traveling wheels 31. Each of the motors 32 with a reduction gear is provided, and the electrode feed mechanism such as the feed carriage and the ball screw shown in the first embodiment is removed.

  The thruster 28 has the same configuration as that shown in the second embodiment, but the traveling wheel 31 includes a direction changing mechanism 33 in addition to the motor 32 with a speed reducer so that it can turn in the longitudinal direction plane. It has become. The direction changing mechanism 33 is driven by a motor 34 with a speed reducer.

  Further, as shown in FIG. 7, the cutting device 8 according to the present embodiment includes a main body frame that penetrates the reactor pressure vessel 1 and is set in a narrow region of a gap with the rising pipe 6 connected to the elbow 5. 13 is provided with a fixing link 24 constituted by a fixing link air cylinder 22 and a pantograph (jack mechanism) 23 on the back side, and along the curved surfaces of the elbow 5 and the rising pipe 6 as shown in FIG. It has a guide bar 36 formed in a shape, can move freely in the vertical direction and the horizontal direction along the shape of the elbow 5 and the rising pipe 6, and can freely change the direction of the course and the direction of the backward path. Yes.

  In the cutting device 8 having such a configuration, the main body frame 13 is adsorbed on the inner wall of the reactor pressure vessel 1 and travels along the inner wall surface, and between the rising pipe 6 or the elbow 5 and the inner wall of the pressure vessel. When the fixed link 24 is set, the fixed link 24 is extended by the driving force of the fixed link air shilling 22, and the guide bar 36 is brought into contact with the rising pipe 6 or the elbow 5.

  When the guide bar 36 is brought into contact with the rising pipe 6 or the like, the main body frame 13 moves the traveling wheel 31 toward the bottom side of the rising pipe 6 or the like by the driving force of the direction changing mechanism 33.

  When the electrode 18 supported by the fixed connection head 35 comes into contact with the edge of the tube cross section A, electric discharge machining is started. While the tube cross section A is being cut by the electric discharge machining of the electrode 18, the traveling wheel 31 is moved accordingly, and the cutting operation of the tube cross section A is advanced.

  As described above, in the present embodiment, the main body frame 13 includes the guide bar 36 so that the cutting device 8 can freely move along the shape of the rising pipe 6, and the cutting device 8 has either the forward direction or the backward direction. Since the body frame 13 is provided with the direction changing mechanism 33 so that it can also move freely in the direction of the direction, the electrode 18 can be fed well under the guide bar 36, the direction changing mechanism 33 and the like.

  Therefore, according to the present embodiment, the cutting device 8 can be accurately and quickly set at the cutting portion of the pipe even in a narrow region, and the working time required for the cutting work can be further shortened. .

  In the above-described embodiment, the rising pipe is shown as an example. However, it is of course possible to use it for a straight pipe and a descending pipe laid out in a narrow area. It is also possible to use the three embodiments supplementarily.

The partial notch conceptual diagram of the reactor pressure vessel in the case of applying the cutting device which concerns on this invention to a reactor pressure vessel as an illustration. 1 is a partially cutaway schematic side view showing a first embodiment of a cutting device according to the present invention. The schematic front view which shows 1st Embodiment of the cutting device which concerns on this invention. The figure which shows the cutting length per electromagnetic unit lateral width, when cut | disconnecting 1/4 piping shape in piping cut | disconnected using the cutting device which concerns on this invention. The schematic front view which shows 2nd Embodiment of the cutting device which concerns on this invention. The schematic front view which shows 3rd Embodiment of the cutting device which concerns on this invention. The schematic side view which shows 3rd Embodiment of the cutting device which concerns on this invention. The partial view which extracted the fixed link and guide bar which were shown in FIG. 7, and was seen from the plane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 2 Control rod drive mechanism part 3a, 3b Nozzle 4 Operating floor floor 5 Elbow 6 Rising pipe 7 Mounting bracket 8 Cutting device 9 Gantry crane 9a Rail 10 Hoist 11 Electrode drive cable 12 Electric discharge machining power cable 13 Body frame 14 Servo Motor 15 Ball Screw 16 Linear Bearing 17 Feeding Cart 18 Electrode 19 Connection 20 Connection Rod 21a, 21b, 21c Clamp 22 Fixed Link Air Shilling 23 Pantograph 24 Fixed Link 25 Insulating Plate 26 Swarf Recovery Hose 27 Swarf Recovery Nozzle 28 Thruster 29 Rotating blade 30 Thruster rotating motor 31 Traveling wheel 32 Motor with speed reducer 33 Direction change mechanism 34 Motor with speed reducer 35 Fixed connecting rod 36 Guide bar 40 Biological shielding wall

Claims (13)

In a cutting apparatus that cuts a pipe disposed through a container, the cutting means body grips and supports the pipe to be cut and a means for positioning and moving the cutting means body along the cross-sectional shape of the pipe And a means for feeding the electrode toward the pipe when the pipe is cut by electric discharge machining from the electrode. 2. The cutting apparatus according to claim 1, wherein the means for positioning the cutting means main body is a fixing ring comprising a fixed link air cylinder and a pantograph. The cutting apparatus according to claim 2, wherein the fixed link includes a guide bar formed in a shape corresponding to a shape of a pipe to be cut. 2. The cutting apparatus according to claim 1, wherein the means for moving the cutting means main body includes a thruster and a traveling wheel. 5. The cutting apparatus according to claim 4, wherein the thruster includes a rotating blade and a thruster rotating motor. The cutting device according to claim 4, wherein the traveling wheel includes a motor with a speed reducer and a direction changing mechanism. The means for feeding the electrode toward the pipe to be cut includes a feed carriage that moves forward and backward on a ball screw, a connecting rod that fixes and supports the feed carriage and the electrode, and a linear bearing that slides the feed carriage. The cutting apparatus according to claim 1, further comprising a cutting apparatus. The cutting apparatus according to claim 7, wherein the ball screw includes a servo motor as a drive source. The cutting device according to claim 7, wherein the connecting rod includes an insulating plate. 2. The cutting apparatus according to claim 1, wherein at least two of the electrodes are joined together, and the joined portions are inclined. 2. The cutting apparatus according to claim 1, wherein the electrode has a shape in which both side portions of the width are thickened and the intermediate portion side is relatively narrowed. The cutting apparatus according to claim 1, wherein the cutting means main body includes a collecting means for collecting cutting powder generated during cutting of the pipe by electric discharge machining of the electrode. The cutting device according to claim 12, wherein the recovery means includes a swarf recovery nozzle and a swarf recovery hose.

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