JP5622868B2 - Welding method, fixing jig and welding apparatus for safe-end piping - Google Patents

Description

  The present invention relates to a welding method for a safe end pipe for welding a nozzle and a safe end pipe, and a fixing jig and a welding apparatus used in the welding method for a safe end pipe.

  Conventionally, a safe end replacement method for replacing a safe end welded to a nozzle (pipe) provided in a reactor pressure vessel is known (see, for example, Patent Document 1). In this replacement method, welding is performed in a state where the axial directions of the nozzle and the safe end are horizontal.

JP 59-199295 A

  By the way, when the weld part is formed by welding the groove part formed between the nozzle and the safe end using the same filler material as the nozzle, A molten portion is formed in which the material on the side and the material on the safe end side melt and melt. In order to improve the quality around the welded portion, it is preferable that the range of the molten portion is small. However, in the conventional welding method, the axial direction of the nozzle and the safe end is horizontal, and the molten nozzle side material and the safe end side material move in the gravitational direction and melt. Become. For this reason, in the conventional welding method, it is difficult to suppress the range of the melted portion.

  Therefore, the present invention provides a safe end pipe welding method and a fixed jig that can improve the quality around a welded portion in which a groove formed between a nozzle and a safe end pipe is welded. It is an object to provide a tool and a welding apparatus.

  A welding method for a safe-end pipe according to the present invention is a method for welding a safe-end pipe that welds a nozzle and a safe-end pipe connecting the nozzle and the pipe, between the nozzle and the safe-end pipe. The groove portion to be formed is formed by axially butting a nozzle-side protruding portion protruding from the end surface of the nozzle and a safe-end protruding portion protruding from the end surface of the safe-end piping. The length in the protruding direction of the side protruding portion is longer than the length in the protruding direction of the safe end protruding portion, while the nozzle is located on the upper side in the vertical direction, while the safe end piping is A welding process for welding the groove portion in a state of being positioned on the lower side in the vertical direction, and in the welding process, the filler material used for welding the groove portion is a material constituting the nozzle side protruding portion. It is the same material as

  According to this configuration, welding can be performed in a state where the nozzle is located on the upper side in the vertical direction and the safe-end piping is located on the lower side in the vertical direction. For this reason, when a groove part is welded using the filler material used as the same material as a nozzle side protrusion part, a part of safe end side protrusion part will fuse | melt by the melt material to fuse | melt. At this time, the melted safe end side protruding portion easily moves downward in the vertical direction due to gravity, and therefore the molten safe end side protruding portion is difficult to be melted into the molten filler material. Moreover, the length in the protrusion direction of the nozzle side protrusion part can be made longer than the length in the protrusion direction of the safe end side protrusion part. For this reason, the range which a safe end side protrusion part fuse | melts can be made small. This makes it possible to reduce the range of the melted portion in which the melted filler material and the melted safe-end protruding portion are melted, so that the quality around the welded portion obtained by welding the groove portion is suitable. Can be.

  In this case, in the welding process, it is preferable to weld the groove portion from the horizontal direction.

  According to this structure, since it can weld with respect to a groove part from a horizontal direction, a filler material can be fuse | melted suitably toward a groove part.

  In this case, the nozzle-side protruding portion is formed by processing a build-up welded portion that is build-up welded to the end surface of the nozzle, using a material different from the material constituting the nozzle as a filler material. Is preferred.

  According to this configuration, for example, by using nickel-based alloy steel such as Inconel (registered trademark) as the overlay welded portion, excellent heat resistance and corrosion resistance are provided between the nozzle and the safe-end piping. Can be.

  The fixing jig of the present invention is a fixing jig that is used in the above-described safe end piping welding method and fixes the nozzle to a predetermined position, and the nozzle is provided so as to protrude from the outer surface of the container. A container mounting portion on which the container can be mounted; a container support portion that supports the container mounting portion; and a container support portion and the container mounting portion, and the protruding direction of the nozzle is vertical. A rotating part that rotates the container mounting part relative to the container support part so as to face the lower side of the direction, a position restricting part that restricts rotation by the rotating part and fixes the container mounting part, It is provided with.

  According to this configuration, the container is placed on the container placement portion, and the container placement portion is rotated with respect to the container support portion via the rotation portion, so that the protruding direction of the nozzle is the lower side in the vertical direction. It can be moved easily so that it faces.

  In this case, it is preferable that the container is provided with a protruding portion that protrudes from the outer surface, and the container mounting portion has a receiving portion that receives and positions the protruding portion.

  According to this configuration, the container can be easily positioned on the container placement portion.

  A welding apparatus of the present invention is a welding apparatus that is used in the above-described method for welding a safe end pipe and welds a groove portion formed between a nozzle and a safe end pipe. A rail provided in the circumferential direction of the pipe for the end, a self-propelled moving portion that self-propels on the rail, and a welding head that is provided in the self-propelled moving portion and welds to the groove portion. Features.

  According to this configuration, the welding head can be easily welded to the groove portion while moving along the rail by the self-propelled moving portion.

  According to the safe end piping welding method, fixing jig, and welding apparatus of the present invention, it is possible to reduce the range of the melted portion in which the filler material and the safe end side protruding portion are melted. The quality around the welded portion formed by welding can be made suitable.

1 is a cross-sectional view of a water chamber mirror provided with a nozzle to be welded by a welding method according to a first embodiment. FIG. 2 is a side view of the fixing jig fixed with the water chamber mirror tilted. FIG. 3 is a side view of a fixing jig that fixes the water chamber mirror in a horizontal state. FIG. 4 is a plan view of a fixing jig fixed with the water chamber mirror in a horizontal state. FIG. 5 is a configuration diagram of a welding apparatus for welding the nozzles. 6 is an explanatory diagram of a groove portion before welding in the welding method of Embodiment 1. FIG. FIG. 7 is an explanatory diagram of a groove portion after temporary fixing in the welding method of the first embodiment. FIG. 8 is an explanatory diagram of a groove portion after temporary outer surface welding in the welding method of the first embodiment. FIG. 9 is an explanatory view of a groove portion after hanging in the welding method of the first embodiment. FIG. 10 is an explanatory diagram relating to a groove portion after inner surface welding. FIG. 11 is an explanatory diagram regarding a groove portion after outer surface welding. FIG. 12 is a configuration diagram of a welding apparatus that welds a nozzle to be welded in the welding method according to the second embodiment. FIG. 13 is an explanatory diagram of a groove portion before welding in the welding method of the second embodiment. FIG. 14 is an explanatory diagram of a groove portion during welding in the welding method of the second embodiment. FIG. 15 is an explanatory diagram of a groove portion after welding in the welding method of the second embodiment. FIG. 16 is an explanatory diagram of a groove portion after post-processing in the welding method of the second embodiment. FIG. 17 is an explanatory diagram of a groove portion before welding in the welding method of the third embodiment. FIG. 18 is an explanatory diagram of a groove portion during welding in the welding method of the third embodiment. FIG. 19 is an explanatory diagram of a groove portion after welding in the welding method of the third embodiment. FIG. 20 is an explanatory diagram of a groove portion after post-processing in the welding method of the third embodiment.

  Hereinafter, with reference to the accompanying drawings, a welding method for a safe end pipe according to the present invention, a fixing jig and a welding apparatus used in the welding method will be described. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  The welding method of the safe end piping according to the present embodiment is a method of connecting a nozzle provided on the outer surface of the container and a safe end piping (hereinafter referred to as a safe end) by welding. In this welding method, the nozzle and the safe end are welded by the welding apparatus in a state where the container is fixed at a predetermined position by the fixing jig. Here, the vessel to be welded is, for example, a pressure vessel of a steam generator used in a pressurized water reactor, and in particular, a water chamber mirror on the lower side in the vertical direction of the pressure vessel. In the present embodiment, the container is described as being applied to a water chamber mirror, but any container having a nozzle can be used. Hereinafter, with reference to FIG. 1, the water chamber mirror used as welding object is demonstrated.

  FIG. 1 is a cross-sectional view of a water chamber mirror provided with a nozzle to be welded by the welding method according to the present embodiment. As shown in FIG. 1, the water chamber mirror 1 constitutes a part of a pressure vessel (not shown) and is formed in a hemispherical shape having a hollow interior. In the water chamber mirror 1, the upper side in the vertical direction is the opening side, and the lower side in the vertical direction is the bottom side. In the water chamber mirror 1, a state where the opening surface is horizontal is a horizontal state, and a state where the opening surface is inclined is an inclined state. The water chamber mirror 1 is made of, for example, low alloy steel, and a bottom 5 of the water chamber mirror 1 has a nozzle 5 protruding outward from the outer surface 1a, and a manhole 6 communicating with the inside and the outside. Is provided.

  The nozzle 5 is formed in a cylindrical shape in which the protruding direction protruding from the outer surface 1a of the water chamber mirror 1 is the axial direction, and a communication port 5a that connects the inside and the outside of the water chamber mirror 1 in the axial direction is formed. Has been. A safe end 10 is welded to the end face of the nozzle 5. The safe end 10 is a short pipe that is made of stainless steel and connects between the nozzle 5 and a pipe (not shown). Since the pipe connected to the nozzle 5 via the safe end 10 is made of stainless steel, the safe end 10 made of stainless steel is welded to the nozzle 5 in advance. The piping can be made of the same material. As a result, the pipe can be easily welded to the nozzle 5 via the safe end 10. In addition, the manhole 6 serves as a work entrance to the interior of the water chamber mirror 1.

  Next, with reference to FIG. 2 thru | or FIG. 4, the fixing jig 20 which fixes the water chamber mirror 1 is demonstrated. 2 is a side view of a fixing jig fixed with the water chamber mirror tilted, and FIG. 3 is a side view of the fixing jig fixed with the water chamber mirror horizontal. These are the top views of the fixing jig fixed in the state which leveled the water chamber mirror. As shown in FIG. 2 to FIG. 4, the fixing jig 20 supports the water chamber mirror 1 so that the water chamber mirror 1 can rotate, and by rotating the water chamber mirror 1, the protruding direction of the nozzle 5 is vertical. It is moved and fixed so as to be on the lower side.

  The fixing jig 20 includes a water chamber mirror mounting portion (container mounting portion) 25 for mounting the water chamber mirror 1, a support portion (container support portion) 26 for supporting the water chamber mirror mounting portion 25, and water. A rotation mechanism (rotation unit) 27 provided between the room mirror mounting unit 25 and the support unit 26 and a position regulation unit 28 that regulates the rotation of the rotation mechanism 27 are provided.

  As shown in FIG. 4, the water chamber mirror mounting portion 25 includes an annular mounting frame 31 having a diameter larger than the diameter on the opening side of the water chamber mirror 1, and the mounting frame 31 toward the radial center. And a plurality of receiving portions 32 provided so as to protrude. The mounting frame 31 can accommodate the water chamber mirror 1 inside thereof. On the outer peripheral surface of the mounting frame 31, a pair of rotating shafts T of the rotating mechanism 27 is provided at positions (left and right sides in the drawing) opposed to each other by 180 °. The mounting frame 31 has a pair of rotating shafts. It is configured to be rotatable about an axis L connecting T. In addition, the outer peripheral surface of the mounting frame 31 is provided with an upper bar attaching portion 33 to which one end of a positioning bar 45 described later is attached at one position (upper side in the figure) on a line orthogonal to the axis L. An upper connection attachment portion 34 to which one end of a connection wire 46 described later is attached is provided at the other position (the lower side in the drawing) on the orthogonal line.

  Although not shown in FIG. 1, a plurality of protrusions 7 are provided on the outer surface 1 a of the water chamber mirror 1 as shown in FIGS. 2 to 4. In the present embodiment, four protrusions 7 are provided, and the four protrusions 7 are provided at equal intervals with a phase shift of 90 ° with respect to the outer surface 1 a of the water chamber mirror 1. In the present embodiment, four receiving portions 32 are provided according to the protruding portion 7, and the four receiving portions 32 are shifted in phase by 90 ° with respect to the mounting frame 31 at equal intervals. Is provided. Accordingly, the four receiving portions 32 can receive and position the four protruding portions 7. The four receiving portions 32 may be configured such that the protruding length in the radial direction can be changed according to the size of the water chamber mirror 1.

  Therefore, when the water chamber mirror 1 is accommodated inside the mounting frame 31, the water chamber mirror mounting portion 25 receives the plurality of protrusions 7 of the water chamber mirror 1 by the plurality of receiving portions 32. The water chamber mirror 1 is positioned on the water chamber mirror mounting portion 25.

  The support portion 26 includes a support base 37 disposed on the ground and a pair of support legs 38 erected on the support base 37. The support base 37 is provided with a lower bar mounting portion 39 to which the other end of a positioning rod 45 described later is mounted at a position below the upper bar mounting portion 33, and at a position below the upper connection mounting portion 34. A lower connection attaching portion 40 to which the other end of the connecting wire 46 is attached is provided.

  The pair of support legs 38 is provided on both sides of the axis L with the water chamber mirror mounting portion 25 interposed therebetween, and supports the water chamber mirror mounting portion 25 via the rotation mechanism 27. Each support leg 38 has a bifurcated shape from the upper side to the lower side in the vertical direction. On the upper side in the vertical direction of the pair of support legs 38, bearing portions 41 of the rotation mechanism 27 are provided.

  The rotation mechanism 27 includes a pair of rotation shafts T provided on the mounting frame 31 and a pair of bearing portions 41 provided on the pair of support legs 38. Therefore, the mounting frame 31 rotates with respect to the pair of support legs 38 by rotating the pair of rotation shafts T with respect to the pair of bearing portions 41.

  The position restricting portion 28 includes a positioning rod 45 that connects the upper bar mounting portion 33 and the lower bar mounting portion 39, and a connection wire 46 that connects the upper connection mounting portion 34 and the lower connection mounting portion 40. And have. The positioning rod 45 includes a long positioning rod 45a and a short positioning rod 45b. When the water chamber mirror 1 is set in the horizontal state, the short positioning rod 45b is used to connect the upper rod mounting portion 33 and the lower positioning rod 45b. The side bar attachment portion 39 is connected. On the other hand, when the water chamber mirror 1 is in an inclined state, the upper rod attaching portion 33 and the lower rod attaching portion 39 are connected using a long positioning rod 45a. The connection wire 46 connects the upper connection attachment portion 34 and the lower connection attachment portion 40 when the water chamber mirror 1 is in an inclined state. As a result, the position restricting unit 28 can more firmly fix the inclined water chamber mirror 1 that is more unstable than the horizontal state by using the connecting wire 46.

  Therefore, when the water chamber mirror 1 is fixed using the fixing jig 20, first, the short positioning rod 45b is attached, and the mounting frame 31 is fixed in the horizontal state. Position and fix to the room mirror mounting portion 25 (see FIG. 3). Thereafter, the short positioning rod 45b is removed, and the water chamber mirror mounting portion 25 is rotated with respect to the support portion 26 via the rotation mechanism 27, so that the protruding direction of the nozzle 5 is set to the lower side in the vertical direction. Move to become. And the elongate positioning rod 45a is attached and the mounting frame 31 (water chamber mirror 1) is fixed to an inclined state (refer FIG. 2). Thereby, the nozzle 5 is located on the upper side in the vertical direction with respect to the safe end 10, and the safe end 10 is located on the lower side in the vertical direction with respect to the nozzle 5. In this state, the nozzle 5 and the safe end 10 are welded using the welding apparatus 50 described below.

  Next, the welding apparatus 50 will be described with reference to FIG. FIG. 5 is a configuration diagram of a welding apparatus for welding the nozzles. This welding apparatus 50 welds the groove part K formed in the perimeter by abutting the nozzle 5 and the safe end 10 in the axial direction. The welding device 50 includes a rail 55 provided on the safe end 10, a self-running moving part 56 that can run on the rail 55, and a welding head 57 attached to the self-running moving part 56.

  The welding head 57 includes a welding electrode 60, an AVC shaft 61, and a wire nozzle (not shown). The welding head 57 is configured to perform, for example, TIG welding as arc welding, and the welding electrode 60 is configured using tungsten or the like. The welding electrode 60 is disposed so that it can be welded from a horizontal direction orthogonal to a groove portion K formed by abutting in the vertical direction. An AVC (Arc Voltage Control) shaft 61 adjusts the distance between the welding electrode 60 and the welding surface, and is controlled by a control device (not shown). The AVC shaft 61 controls the distance of the welding electrode 60 to the welding surface so that the voltage between the welding electrode 60 and the welding surface is constant, thereby making the distance of the welding electrode 60 to the welding surface constant. The wire nozzle supplies the supplied welding wire (melting material) to the predetermined supply position with respect to the welding electrode 60. Here, the welding wire used when welding the groove portion K is made of nickel-based alloy steel such as Inconel (registered trademark).

  The rail 55 has an inner peripheral rail 55 a provided on the inner peripheral surface of the safe end 10 and an outer peripheral rail 55 b provided on the outer peripheral surface of the safe end 10. The inner peripheral rail 55 a and the outer peripheral rail 55 b are extended in the circumferential direction along the peripheral surface of the safe end 10.

  The self-propelled moving unit 56 moves on the rail 55 at a predetermined speed. The wire reel 58 that supplies the welding wire toward the wire nozzle is attached to the self-propelled moving portion 56.

  Therefore, when welding the groove part K by the welding head 57, the welding apparatus 50 generates arc discharge from the welding electrode 60 and melts the welding wire supplied from the wire nozzle, thereby the groove part K. Weld to. At this time, the welding head 57 performs welding over the entire circumference of the groove portion K while moving on the rail 55 by the self-running moving portion 56. Here, when the groove portion K is welded from the outer peripheral side, two welding devices 50 are used, and the two welding devices 50 are arranged on the outer peripheral rail 55b so that the phases are shifted by 180 °. Then, on the outer peripheral rail 55b, the two welding apparatuses 50 are rotated in the same direction to perform welding, and if the two welding apparatuses 50 make a half turn, welding is performed over the entire circumference of the groove portion K. It can be carried out. On the other hand, when welding the groove part K from the inner peripheral side, one welding device 50 is used, and welding is performed by rotating one welding device 50 on the inner peripheral rail 55a.

  Next, with reference to FIG. 6 thru | or FIG. 11, the welding method of the safe end 10 using the fixing jig 20 and the welding apparatus 50 is demonstrated. 6 is an explanatory diagram regarding the groove portion before welding, FIG. 7 is an explanatory diagram regarding the groove portion after temporary fixing, and FIG. 8 is an explanatory diagram regarding the groove portion after temporary outer surface welding. . Moreover, FIG. 9 is explanatory drawing regarding the groove part after a backhang, FIG. 10 is explanatory drawing regarding the groove part after inner surface welding, and FIG. 11 is explanatory drawing regarding the groove part after outer surface welding. It is. In this welding method, a groove aligning step, a temporary fixing step, a first outer surface welding step, a back surface hanging step, an inner surface welding step, and a second outer surface welding step are sequentially performed. The groove alignment step and the temporary fixing step are performed before the water chamber mirror 1 is fixed to the fixing jig 20.

  As shown in FIG. 6, in the groove alignment process, the groove portion K is formed over the entire circumference by abutment of the nozzle 5 and the safe end 10 in the axial direction. Here, the configuration around the groove portion K will be specifically described. The groove portion K formed between the nozzle 5 and the safe end 10 includes a nozzle-side protruding portion 71 protruding from the end surface of the nozzle 5 and a safe-end protruding portion 72 protruding from the end surface of the safe end 10. Are formed in the axial direction. The nozzle-side protruding portion 71 is formed by processing a build-up weld 75 that is welded to the end surface of the nozzle 5 using nickel-based alloy steel such as Inconel (registered trademark). The safe end side protrusion 72 is formed by processing the end surface of the safe end 10. At this time, the length L1 in the protruding direction of the nozzle-side protruding portion 71 is formed longer than the length L2 in the protruding direction of the safe end-side protruding portion 72.

  As shown in FIG. 7, in the temporary fixing step after the groove alignment step, the nozzle 5 and the safe end 10 are connected by a connecting piece 80. The connection piece 80 is formed in a rectangular block shape, and a plurality of connection pieces 80 are provided in the circumferential direction along the inner peripheral surfaces of the nozzle 5 and the safe end 10. One end of the connecting piece 80 in the longitudinal direction is attached to the inner peripheral surface of the nozzle 5, and the other end in the longitudinal direction is attached to the inner peripheral surface of the safe end 10.

  As shown in FIG. 8, in the first outer surface welding process after the temporary fixing process, welding is performed in the horizontal direction from the outer peripheral side of the groove portion K by using two welding apparatuses 50, so that the welded portion M <b> 1 is formed. Form. At this time, the welding wire used in the welding apparatus 50 is made of nickel-based alloy steel, which is the same material as the nozzle-side protruding portion 71. In the first outer surface welding process, welding is performed so that the welded portion M1 is positioned inside the thickness of the groove portion K in the horizontal direction.

  As shown in FIG. 9, in the hanging process after the first outer surface welding process, the connecting piece 80 that connects the nozzle 5 and the safe end 10 is removed. Thereafter, in the suspension process, the nozzle-side protruding portion 71 and the safe-end-side protruding portion 72 are removed from the inner peripheral side of the groove portion K while leaving the welded portion M1 welded in the first outer surface welding step. Sharpen like so.

  As shown in FIG. 10, in the inner surface welding process after the suspension process, a welded part M2 is formed by performing welding in the horizontal direction from the inner peripheral side of the groove part K using one welding device 50. To do. Also at this time, the welding wire used in the welding apparatus 50 is made of nickel-based alloy steel, which is the same material as the nozzle side protrusion 71. In the inner surface welding process, welding is performed so that the welded part M2 exceeds the inner peripheral surfaces of the nozzle 5 and the safe end 10.

  As shown in FIG. 11, in the second outer surface welding step after the inner surface welding step, welding is performed in the horizontal direction from the outer peripheral side of the groove portion K by using two welding apparatuses 50, so that the welded portion M <b> 3 is formed. Form. Also at this time, the welding wire used in the welding apparatus 50 is made of nickel-based alloy steel, which is the same material as the nozzle side protrusion 71. In the second outer surface welding process, welding is performed so that the welded part M3 exceeds the outer peripheral surfaces of the nozzle 5 and the safe end 10.

  By performing each process in order as described above, the nozzle 5 and the safe end 10 can be connected by welding. Thereafter, in the post-processing step, the welded portion M2 on the inner peripheral surface side is shaved with a grinder or the like so as to be flush with the inner peripheral surface of the nozzle 5 and the safe end 10, and similarly, on the outer peripheral surface side. The welded part M3 is ground with a grinder or the like so as to be flush with the outer peripheral surfaces of the nozzle 5 and the safe end 10.

  As described above, according to the welding method of the first embodiment, welding can be performed in a state where the nozzle 5 is located on the upper side in the vertical direction and the safe end 10 is located on the lower side in the vertical direction. For this reason, if the groove part K is welded using the welding wire which becomes the same material as the nozzle side protrusion part 71, a part of safe end side protrusion part 72 will melt | dissolve with the welding wire to fuse | melt. At this time, the welding wire to be melted, that is, the welded portions M1, M2, and M3 are on the upper side in the vertical direction of the safe end side protruding portion 72, and the safe end side protruding portion 72 to be melted is in the vertical direction by gravity. It becomes easy to move toward the lower side of the. In this case, the melted safe end side protrusion 72 is less likely to be melted into the welds M1, M2, and M3. Thereby, since the range of the fusion | melting part into which welded part M1, M2, M3 and the safe end side protrusion part 72 to melt | dissolve can be made small, the quality around welding part M1, M2, M3 is suitable. Can be.

  Moreover, the length L1 in the protruding direction of the nozzle-side protruding portion 71 can be made longer than the length L2 in the protruding direction of the safe end-side protruding portion 72. For this reason, the range which the safe end side protrusion part 72 fuse | melts can be made small. Therefore, since the range of the melted part where the welded parts M1, M2, M3 and the melted safe end side protruding part 72 melt can be further reduced, the quality around the welded parts M1, M2, M3 is suitable. Can be.

  Further, since the welding apparatus 50 can weld the groove portion K from the horizontal direction, the welding wire can be suitably melted toward the groove portion K.

  Further, by forming a build-up weld 75 on the end face of the nozzle 5 using nickel-based alloy steel such as Inconel (registered trademark), heat resistance is ensured between the nozzle 5 and the safe end 10. And excellent corrosion resistance.

  Further, by using the fixing jig 20, the water chamber mirror 1 is mounted on the water chamber mirror mounting portion 25, and the water chamber mirror mounting portion 25 is rotated with respect to the support portion 26 via the rotation mechanism 27. By doing so, the fixing jig 20 can easily direct the protruding direction of the nozzle 5 to the lower side in the vertical direction.

  Further, in the fixing jig 20, by providing a plurality of receiving portions 32 on the water chamber mirror mounting portion 25, the fixing jig 20 can easily position and mount the nozzle 5.

  Further, by using the welding apparatus 50, the welding head 57 can be easily welded to the groove portion K over the entire circumference while moving along the rail 55 by the self-propelled moving portion 56.

  Then, the welding method of the safe end piping which concerns on Example 2, the fixing jig used for this welding method, and a welding apparatus are demonstrated. In the second embodiment, only parts different from the first embodiment will be described in order to avoid redundant description. In the welding method of the safe-end piping 10 of the first embodiment, the groove portion K is welded from the inner peripheral side and the outer peripheral side. However, in the welding method of the safe-end piping 100 of the second embodiment, the opening is opened. The tip K is welded only from the outer peripheral side. Here, the welding apparatus 150 will be described with reference to FIG. Note that the fixing jig 20 is the same as that of the first embodiment, and thus the description thereof is omitted.

  FIG. 12 is a configuration diagram of a welding apparatus that welds a nozzle to be welded in the welding method according to the second embodiment. As shown in FIG. 12, two welding apparatuses 150 are provided on the outer peripheral side of the safe end 100, and are arranged with a 180 ° phase shift so as to face each other with the safe end 100 interposed therebetween. The two welding apparatuses 150 are traveling on a common rail, the rail 155 provided in the safe end 100, the two self-propelled moving units 156 capable of self-propelling on the rail 155, and the two self-propelling units. Two welding heads 157 attached to the moving part 156 are provided.

  Each welding head 157 includes a welding electrode 160, an AVC shaft 161, and a wire nozzle (not shown). The welding electrode 160 is made of tungsten or the like, and is disposed so as to be welded from a horizontal direction orthogonal to a groove portion K formed by abutting in the vertical direction. At this time, the extending direction of the welding electrode 160 of one welding head 157 and the welding electrode 160 of the other welding head 157 out of the two welding heads 157 is slightly inclined with respect to the horizontal direction. Yes. That is, the welding electrode 160 of one welding head 157 is inclined slightly downward with respect to the horizontal direction because the distal end side thereof is located on the lower side in the vertical direction with respect to the proximal end side. Further, the welding electrode 160 of the other welding head 157 is inclined slightly upward with respect to the horizontal direction because its distal end side is located above the proximal end side in the vertical direction. That is, each welding head 157 can be welded to the groove portion K from the horizontal direction with the welding electrode 160 inclined.

  Each AVC (Arc Voltage Control) shaft 161 adjusts the distance between each welding electrode 160 and the welding surface, and is controlled by a control device (not shown). The AVC shaft 161 keeps the distance of the welding electrode 60 to the welding surface by controlling the distance of the welding electrode 60 to the welding surface so that the voltage between the welding electrode 160 and the welding surface becomes constant. Each wire nozzle supplies the supplied welding wire (melting material) to each welding electrode 60 to a predetermined supply position. Here, the welding wire used when welding the groove portion K is made of nickel-based alloy steel such as Inconel (registered trademark).

  The rail 155 includes only an outer peripheral rail 155 b provided on the outer peripheral surface of the safe end 100. The outer peripheral rail 155 b extends in the circumferential direction along the peripheral surface of the safe end 100.

  The self-propelled moving unit 156 moves on the rail 155 at a predetermined speed. A wire reel 158 that supplies a welding wire toward the wire nozzle is attached to the self-propelled moving portion 156.

  Therefore, each welding device 150 generates arc discharge from the welding electrode 60 and melts the welding wire supplied from the wire nozzle when welding the groove portion K by the welding head 157, thereby the groove portion. Weld to K. At this time, each welding head 157 performs welding over the entire circumference of the groove portion K while moving on the rail 155 by the self-running moving portion 156. Here, when welding the groove part K from the outer peripheral side using two welding apparatuses 150, welding is performed by rotating the two welding apparatuses 150 in the same direction on the outer peripheral rail 155b. At this time, one welding apparatus 150 performs welding on the lower side of the groove portion K because the welding electrode 160 is inclined downward with respect to the horizontal direction. The other welding device 150 performs welding on the upper side of the groove portion K because the welding electrode 160 is inclined upward with respect to the horizontal direction. For this reason, when the two welding apparatuses 150 perform welding over the entire circumference of the groove portion K, welding is alternately performed on the lower side and the upper side of the groove portion K.

  Next, a method for welding the safe end 100 using the fixing jig 20 and the two welding apparatuses 150 will be described with reference to FIGS. FIG. 13 is an explanatory diagram of a groove portion before welding in the welding method of the second embodiment, and FIG. 14 is an explanatory diagram of the groove portion during welding in the welding method of the second embodiment. FIG. 15 is an explanatory view of the groove portion after welding in the welding method of the second embodiment, and FIG. 16 is an explanatory view of the groove portion after post-processing in the welding method of the second embodiment. In this welding method, a groove alignment process and an outer surface welding process are performed in order.

  As shown in FIG. 13, in the groove aligning step, the groove 5 is fitted over the entire circumference by abutting the nozzle 5 of the water chamber mirror 1 fixed to the fixing jig 20 and the safe end 100 in the axial direction. Part K is formed. Here, the configuration around the groove portion K will be specifically described. The groove portion K formed between the nozzle 5 and the safe end 100 includes a nozzle-side protruding portion 171 protruding from the end surface of the nozzle 5 and a safe-end protruding portion 172 protruding from the end surface of the safe end 100. Are formed in the axial direction. Here, the inner peripheral surface of the nozzle base 5 has different inner diameters on the base end side (the upper side in the drawing) and the end surface side (the lower side in the drawing). The diameter is larger than the inner diameter on the base end side. That is, on the end surface side of the inner peripheral surface of the nozzle 5, an inner peripheral convex portion 180 that protrudes as compared with the proximal end side of the inner peripheral surface of the nozzle 5 is formed. The thickness of the end face side of the nozzle 5 on which the inner peripheral convex portion 180 is formed is thicker than the thickness on the proximal end side of the nozzle 5 on which the inner peripheral convex portion 180 is not formed. . In addition, this inner peripheral side convex part 180 is scraped off in a post-processing step after welding so that the thickness of the end face side of the nozzle 5 is the same as the thickness of the base end side.

  The nozzle-side protruding portion 171 is formed by processing a build-up weld 175 that is build-up welded to the end surface of the nozzle 5 using a nickel-based alloy steel such as Inconel (registered trademark). The build-up weld 175 is formed to have the same thickness as the end face side of the nozzle 5 on which the inner peripheral convex portion 180 is formed. And the nozzle side protrusion part 171 is located in the radial inside rather than the inner peripheral surface of the base end side of the nozzle 5 so that it may be located in the edge part inside radial direction, ie, the inner peripheral side convex part 180. And are formed so as to overlap in the axial direction.

  The safe end side protrusion 172 is formed by processing the end surface of the safe end 100 made of stainless steel, as in the first embodiment. The safe end 100 is formed such that at least the thickness of the end abutted on the nozzle 5 side is the same as the thickness on the end surface side of the nozzle 5 on which the inner peripheral convex portion 180 is formed. And the safe end side protrusion part 172 is located in the radial inside rather than the internal peripheral surface of the base end side of the nozzle 5 so that it may be located in the edge part inside radial direction, and the inner peripheral side convex part 180. And are formed so as to overlap in the axial direction.

  Further, the length L1 in the protruding direction of the nozzle-side protruding portion 171 is formed longer than the length L2 in the protruding direction of the safe end-side protruding portion 172.

  As shown in FIG. 14, in the outer periphery welding process after the groove alignment process, welding is performed in the horizontal direction from the outer periphery side of the groove portion K by using two welding apparatuses 150, thereby forming a welded portion M <b> 4. To do. At this time, the welding wire used in the welding apparatus 150 is made of nickel-based alloy steel, which is the same material as the nozzle side protruding portion 171. In the outer periphery welding process, when forming the welded portion M4, welding is performed on the lower side of the groove portion K by one welding device 150, and welding is performed on the upper side of the groove portion K by the other welding device 150. Then, when the two welding apparatuses 150 move around the outer periphery of the groove portion K in the same circumferential direction, the upper side welding and the lower side welding with respect to the groove portion K are alternately performed. Thereby, even if it is a case where the space formed by the end surface of the overlay welding part 175 and the end surface of the safe end 100 is wide by abutting the groove part K, welding can be performed suitably. Then, as shown in FIG. 15, in the outer periphery welding process, welding is performed so that the welded part M <b> 4 exceeds the outer peripheral surfaces of the nozzle 5 and the safe end 100.

  By performing each process in order as described above, the nozzle 5 and the safe end 100 can be connected by welding. Thereafter, in the post-processing step, the nozzle 5 is formed so as to have the same thickness as the base end side of the nozzle 5, that is, so that the inner peripheral surfaces of the nozzle 5 and the safe end 100 are flush with each other. The inner peripheral convex portion 180, the inner peripheral surface of the overlay welded portion 175, the groove portion K after welding, a part of the welded portion M4, and the inner peripheral surface of the safe end 100 are scraped by machining using a grinder or the like. It is. Similarly, in the post-processing step, the weld portion M4 on the outer peripheral surface side is scraped off by machining using a grinder or the like so as to be flush with the outer peripheral surfaces of the nozzle 5 and the safe end 100.

  As described above, according to the welding method of the second embodiment, the groove portion K can be welded only from the outer peripheral side, so that the welding from the inner peripheral side is omitted compared to the welding method of the first embodiment. As a result, the time required for the welding operation can be shortened. Further, the number of welding apparatuses 150 used in the welding method of the second embodiment is reduced as compared with the welding apparatus 150 used in the welding method of the first embodiment because the welding apparatus 150 on the inner peripheral surface side can be omitted. be able to. For this reason, the time required for the installation work of the welding apparatus 150 can also be shortened.

  Then, the welding method of the safe end piping which concerns on Example 3, the fixing jig used for this welding method, and a welding apparatus are demonstrated. In Example 3, parts different from Example 2 will be described in order to avoid redundant description. In the welding method of the safe end pipe 100 of the second embodiment, welding is performed on the groove portion K only from the outer peripheral side, and the nozzle side protruding portion 171 (the overlay weld portion 175) is made of nickel-based alloy steel. The safe end side protrusion part 172 (safe end 100) was comprised using stainless steel. In the welding method of the safe end pipe 200 according to the third embodiment, the groove portion K is welded only from the outer peripheral side, and the nozzle side protruding portion 271 is made of stainless steel, and the safe end protruding portion. 272 is made of stainless steel. That is, in Example 3, the nozzle side protrusion part 271 and the safe end side protrusion part 272 are comprised with the same material. Here, a welding method of the safe end 100 using the fixing jig 20 and the two welding apparatuses 150 will be described with reference to FIGS. Note that the fixing jig 20 and the two welding apparatuses 150 are the same as those in the second embodiment, and thus the description thereof is omitted.

  FIG. 17 is an explanatory diagram of a groove part before welding in the welding method of Example 3, and FIG. 18 is an explanatory diagram of the groove part during welding in the welding method of Example 3. FIG. 19 is an explanatory diagram of a groove portion after welding in the welding method of Example 3, and FIG. 20 is an explanatory diagram of the groove portion after post-processing in the welding method of Example 3. In this welding method, as in the second embodiment, the groove alignment step and the outer surface welding step are performed in order. In the welding method of the third embodiment, parts different from the second embodiment will be described.

  As shown in FIG. 17, the nozzle-side protruding portion 271 is formed by processing a build-up weld portion 275 that is build-up welded to the end surface of the nozzle 5 using stainless steel. The nozzle-side protruding portion 271 is positioned at the radially inner end, that is, positioned radially inward of the inner peripheral surface on the proximal end side of the nozzle 5 and the inner peripheral convex portion 280 and the shaft. It is formed to overlap in the direction.

  Similarly to the second embodiment, the safe end-side protruding portion 272 is formed by processing the end surface of the safe end 200 made of stainless steel. The safe-end-side projecting portion 272 is positioned at the radially inner end, that is, located radially inward of the inner peripheral surface on the proximal end side of the nozzle 5 and the inner peripheral-side convex portion 280 and the shaft It is formed to overlap in the direction.

  The length L1 in the protruding direction of the nozzle-side protruding portion 271 is formed to be the same length as the length L2 in the protruding direction of the safe end-side protruding portion 272.

  As shown in FIG. 18, in the outer periphery welding process after the groove alignment process, the weld M <b> 4 is formed by performing welding in the horizontal direction from the outer periphery side of the groove K using two welding apparatuses 150. To do. At this time, the welding wire used in the welding apparatus 150 is made of stainless steel, which is the same material as the nozzle side protruding portion 271 and the safe end side protruding portion 272. In the outer periphery welding process, when forming the welded portion M4, first, welding is performed on the center of the groove portion K in the vertical direction using one of the two welding apparatuses 150. Thereafter, in the outer periphery welding process, welding is performed on the lower side of the groove portion K by one welding device 150, and welding is performed on the upper side of the groove portion K by the other welding device 150. Then, when the two welding apparatuses 150 move around the outer periphery of the groove portion K in the same circumferential direction, the upper side welding and the lower side welding with respect to the groove portion K are alternately performed. Then, as shown in FIG. 19, in the outer periphery welding process, welding is performed so that the welded part M <b> 4 exceeds the outer peripheral surfaces of the nozzle 5 and the safe end 200.

  By performing each process in order as described above, the nozzle 5 and the safe end 200 can be connected by welding. Thereafter, in the post-processing step, the nozzle 5 is adjusted to have the same thickness as that of the proximal end of the nozzle 5, that is, the inner peripheral surfaces of the nozzle 5 and the safe end 200 are flush with each other. The inner peripheral convex portion 280, the inner peripheral surface of the overlay welded portion 275, the groove portion K after welding, a part of the welded portion M4, and the inner peripheral surface of the safe end 200 are scraped by machining using a grinder or the like. It is. Similarly, in the post-processing step, the weld portion M4 on the outer peripheral surface side is scraped off by machining using a grinder or the like so as to be flush with the outer peripheral surfaces of the nozzle 5 and the safe end 200.

  As described above, according to the welding method of Example 3, since welding can be performed only on the groove portion K from the outer peripheral side, welding from the inner peripheral side is omitted compared to the welding method of Example 1. As a result, the time required for the welding operation can be shortened. Further, the number of welding apparatuses 150 used in the welding method of the third embodiment is reduced as compared with the welding apparatus 150 used in the welding method of the first embodiment because the welding apparatus 150 on the inner peripheral surface side can be omitted. be able to. For this reason, the time required for the installation work of the welding apparatus 150 can also be shortened.

  In Examples 2 and 3, welding was performed only from the outer peripheral side, but welding may be performed only from the inner peripheral side. In this case, it is preferable that the configuration around the groove portion K is opposite between the outer peripheral side and the inner peripheral side, and the two welding apparatuses 150 are provided on the inner peripheral side, It is preferable to perform welding from the circumferential side.

  Further, in Examples 2 and 3, the groove portion K was welded by alternately performing the upper side welding and the lower side welding on the groove portion K. However, when the space formed by the end faces of the build-up welds 175 and 275 and the end faces of the safe ends 100 and 200 is narrowed by abutting the groove portions K, only at the center in the vertical direction of the groove portions K. Welding may be performed,

  Further, in Examples 2 and 3, the welding electrode 160 is inclined so as to be upward and downward. However, also in Example 1, the welding electrode 60 of the two welding apparatuses 50 on the outer peripheral side may be inclined. . That is, the welding electrode 60 may be inclined as long as the groove portion K can be welded from the horizontal direction.

Moreover, in Example 2, the nozzle side protrusion part 171 and the safe end side protrusion part 172 are made of different materials, and in Example 3, the nozzle side protrusion part 271 and the safe end side protrusion part 272 are made of the same material. However, also in Example 1, it is good also considering the nozzle side protrusion part 71 and the safe end side protrusion part 72 as the same material.

  As described above, the safe end pipe welding method, the fixing jig, and the welding apparatus according to the present invention are useful when welding a nozzle and a safe end pipe made of different materials, Suitable for welding safe-end piping to the nozzle provided in the water chamber mirror.

DESCRIPTION OF SYMBOLS 1 Water chamber mirror 5 Tubular base 6 Manhole 7 Protruding part 10 Safe end 20 Fixing jig 25 Water chamber mirror mounting part 26 Support part 27 Rotating mechanism 28 Position control part 31 Mounting frame 32 Receiving part 37 Support stand 38 Support leg DESCRIPTION OF SYMBOLS 41 Bearing part 45 Positioning rod 46 Connecting wire 50 Welding device 55 Rail 56 Self-propelled moving part 57 Welding head 58 Wire reel 71 Protrusion side protrusion part 72 Safe end side protrusion part 75 Overlay welding part 80 Connection piece 100 Safe end piping (Example 2)
150 Welding device (Example 2)
155 rail (Example 2)
156 Self-propelled moving part (Example 2)
157 Welding head (Example 2)
158 Wire reel (Example 2)
171 Tubular side protrusion (Example 2)
172 Safe end side protrusion (Example 2)
175 Overlay weld (Example 2)
180 Inner peripheral side convex part (Example 2)
200 Safe-end piping (Example 3)
271 Tube side protrusion (Example 3)
272 Safe end side protrusion (Example 3)
275 Overlay weld (Example 3)
280 Inner peripheral side convex part (Example 3)
T rotation axis L axis line K groove portion L1 length of nozzle-side protruding portion L2 length of safe-end side protruding portion M1 welded portion formed in first outer surface welding process M2 welded portion formed in inner surface welding step M3 Welded part formed in the second outer surface welding process M4 Welded part formed in the outer surface welding process

Claims (9)

In a welding method for a safe end pipe for welding a nozzle base and a safe end pipe connecting the nozzle base and the pipe,
A groove portion formed between the nozzle and the safe end pipe includes a nozzle-side protruding portion protruding from an end surface of a build-up welded portion that is overlay welded to an end surface of the nozzle, and the safe It is formed by abutting the safe end side protruding part protruding from the end face of the end pipe in the axial direction,
The length in the protruding direction of the nozzle side protruding portion is longer than the length in the protruding direction of the safe end protruding portion,
While the nozzle is positioned on the upper side in the vertical direction, the safe end pipe is positioned on the lower side in the vertical direction, and includes a welding step of performing welding on the groove portion,
In the welding step, the filler material used for welding the groove portion is the same material as the material constituting the nozzle-side protruding portion.   The welding method for a safe end pipe according to claim 1, wherein in the welding step, welding is performed on the groove portion from a horizontal direction.   The said nozzle side protrusion part is formed by processing the build-up welding part which is build-up welded to the end surface of the said nozzle, using the material different from the material which comprises the said nozzle as a filler material. The method for welding safe-end piping according to claim 1 or 2. Wherein in the welding step, to said groove portion, one of the claims 1 to 3, characterized in that welding is performed from either side of the tube block and the inner circumferential side or outer circumferential side of the safe end pipe A welding method for the safe-end piping according to claim 1. The groove portion after welding claims, characterized from the other side on the opposite side with respect to either side of the inner circumferential side or outer circumferential side welding has been performed, to be scraped off by machining 4. A welding method for the safe-end piping according to 4 . A fixing jig that is used in the method for welding a safe-end pipe according to any one of claims 1 to 5 , and fixes the nozzle to a predetermined position,
The nozzle is provided so as to protrude from the outer surface of the container,
A container placement unit capable of placing the container;
A container support portion for supporting the container placement portion;
A rotation is provided between the container support part and the container placement part, and rotates the container placement part relative to the container support part so that the protruding direction of the nozzle is directed downward in the vertical direction. Moving part,
A fixing jig comprising: a position restricting portion that restricts rotation by the rotating portion and fixes the container placing portion. The container is provided with a protruding portion protruding from the outer surface,
The fixing jig according to claim 6 , wherein the container mounting portion has a receiving portion that receives and positions the protruding portion. It claims 1 used in a method of welding piping safe end according to any one of 5, with respect to the groove portion formed between the safe end pipe with the pipe base, performs welding A welding device,
Rails provided in the circumferential direction of the safe-end piping;
A self-propelled moving part that self-propels on the rail;
A welding apparatus comprising: a welding head that is provided in the self-propelled moving part and welds the groove part. The rail is provided on one side of either the inner peripheral side or the outer peripheral side of the safe-end piping,
The welding apparatus according to claim 8 , wherein the welding head performs welding from either one of an inner peripheral side and an outer peripheral side on which the rail is provided.

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