WO2012066956A1

WO2012066956A1 - Welding jig and welding device for control rod drive device housing

Info

Publication number: WO2012066956A1
Application number: PCT/JP2011/075576
Authority: WO
Inventors: 志津雄井上
Original assignee: 三菱重工業株式会社
Priority date: 2010-11-16
Filing date: 2011-11-07
Publication date: 2012-05-24
Also published as: JP2012106255A

Abstract

Provided is a welding jig (1) for a control rod drive device housing for welding, along a circumference, a canopy seal (166) provided in a circumferential form in the control rod drive device housing formed in a cylindrical shape, the welding jig (1) comprising a jig main body (2), a gas introduction portion (3), a welding torch disposing portion (4), and a guide portion (5). The jig main body (2) is formed in an annular shape along the circumference of the canopy seal (166) and is disposed so that an inner circumferential surface is faced to a groove portion of the canopy seal (166). The gas introduction portion (3) has an introduction opening (3a) on an outer side of the annular shape of the jig main body (2) and a discharge opening on the side of the inner circumferential surface of the jig main body (2), to penetrate the inside of the jig main body (2). The welding torch disposing portion (4) is formed by notching a part of the jig main body (2) and causes the outside of the annular shape of the jig main body (2) and the inside thereof to communicate with each other. The guide portion (5) is provided to the jig main body (2) and holds the jig main body (2) so that the inner circumferential surface of the jig main body (2) is disposed on the position opposed to the groove portion of the canopy seal (166) by being in contact with the control rod drive device housing.

Description

Welding jig and welding device for control rod drive device housing

The present invention relates to a welding jig and a welding device for a control rod drive device housing, which are used for assembling and repairing a control rod drive device that is arranged on the upper part of a reactor vessel and puts control rods in and out of a reactor core.

Pressurized Water Reactor (PWR) adjusts the number of neutrons by absorbing neutrons generated in the core with a control rod and controls the reactor output. For this reason, a plurality of control rods are dispersed and incorporated in advance in the fuel assembly constituting the core, and are controlled collectively. Each control rod is taken in and out of the core by a control rod drive device (CRDM: control rod drive mechanism) arranged at the top of the reactor vessel.

In general, a magnetic jack is often used as a control rod driving device for a pressurized water reactor. This magnetic jack moves a latch that intermittently grips the control rod drive shaft using electromagnetic force to drive the control rod drive shaft in the axial direction. It is stored. The control rod drive device housing is composed of a drive shaft housing that houses the control rod drive shaft, a latch housing that surrounds the drive shaft housing and houses electromagnetic coils and latches, and a cap that closes the upper end of the drive shaft housing. Yes. The lower end of the latch housing is connected to a nozzle that is welded through the reactor vessel lid. The drive shaft housing is inserted from the upper end of the latch housing and connected to the latch housing. The cap is connected to the upper end of the drive shaft housing. Assuming that the control rod drive shaft has failed, in order to take out the control rod drive shaft, the nozzle and the latch housing, the latch housing and the drive shaft housing, the drive shaft housing and the cap can be separated from each other by screw connection. It is connected to. In addition, because the inside of the control rod drive unit housing communicates with the high-temperature and high-pressure coolant space inside the reactor vessel lid, it is possible that the coolant leaks along the screw surface, so the outer end of the joint screw surface The side is closed by circumferential seal welding called a canopy seal. This canopy seal has a dome-shaped cross section, has little change in the cross-sectional shape of the welded portion, suitably seals the high pressure of the coolant passing through the thread surface, and is easy to cut during disassembly (for example, Patent Documents) 1).

When assembling or repairing such a control rod drive device, the canopy seal of the control rod drive device housing is welded. The canopy seal is circumferentially aligned along the outer diameter of the control rod drive device housing. Since it is provided in a shape, it must be welded along the circumference, and since the inside is sealed, a shielding gas for TIG welding must be introduced from the outside. For this reason, conventionally, an insert ring is temporarily attached to the groove portion of the canopy seal, and it is welded in a circumferential shape while injecting a shielding gas through a notch hole provided in a part of the insert ring like injection. It was. Such welding work is very time-consuming and has a problem that the shielding gas is trapped in the canopy seal.

In addition, for example, the single-sided TIG welding method described in Patent Document 2 describes that a weld bead is formed on an object to be welded by moving a shield gas while ejecting it from a welding torch. However, it is not easy to weld the circumferential portion such as the canopy seal described above while providing a space for the shield gas, and it is difficult to solve the above-described problem.

JP-A-10-123276 JP 59-24578 A

The present invention solves the above-described problems, and an object thereof is to provide a welding jig and a welding apparatus for a control rod drive device housing that can be appropriately welded with a shielding gas and can be easily welded. .

In order to achieve the above-mentioned object, a welding jig for a control rod drive device housing according to the present invention has a canopy seal provided circumferentially in a control rod drive device housing formed in a cylindrical shape along the circumference. A welding jig for a control rod drive device housing for welding, which is formed in an annular shape along the circumference of the canopy seal, and is disposed with an inner circumferential surface facing a groove portion of the canopy seal. A tool main body, a gas introduction part having an introduction port on the annular outer side of the jig main body and having a discharge port on the inner peripheral surface side of the jig main body and penetrating through the inside of the jig main body, A part of the jig body is cut out and formed, and a welding torch arrangement portion that opens the annular outer side and the inner side of the jig body, and the jig body comes in contact with the control rod drive device housing The inner peripheral surface of the jig body Characterized in that it comprises a guide portion for holding the jig body so that the position opposed to the groove portion of the canopy seal.

According to the welding jig of the control rod drive device housing, the shield gas is supplied from the introduction port of the gas introduction part, and the jig body is rotated along the circumference of the canopy seal, and the welding torch is arranged at the position. The groove portion of the canopy seal is welded with the arranged welding torch. Thereby, the shield gas at the time of welding can be suitably introduced into the groove portion, and welding can be easily performed along the circumference of the canopy seal.

Further, the welding jig of the control rod drive device housing of the present invention is further characterized by further comprising an opening / closing part for opening and closing the annular shape of the jig body.

According to the welding jig for the control rod driving device housing, the jig main body can be easily mounted around the cylindrical control rod driving device housing by opening the annular shape of the jig main body by the opening / closing part. .

In order to achieve the above-mentioned object, a welding apparatus for a control rod drive device housing according to the present invention welds a canopy seal provided circumferentially in a control rod drive device housing formed in a cylindrical shape along the circumference. A control rod driving device housing welding device for fixing the control rod driving device housing, and a fixing portion fixed to the control rod driving device housing, and a rotation provided on the fixing portion in a manner of rotating around the control rod driving device housing A welding jig supporting portion that is provided in the rotating portion and supports the above-described welding jig at the position of the groove portion of the canopy seal, and welding of the welding jig provided in the rotating portion. And a welding torch support part for arranging the welding torch on the torch arranging part.

According to the welding apparatus for the control rod drive device housing, the welding jig is attached to the welding jig support portion, and the welding apparatus is fixed to the nozzle by the fixing portion, and the shield gas is supplied to the welding jig to perform welding. By applying a voltage to the electrode of the torch and rotating the rotating part, the groove part of the canopy seal can be welded while supplying the shielding gas along the circumference of the canopy seal. As a result, a shield gas during welding can be appropriately introduced into the groove portion, and welding can be easily performed along the circumference of the canopy seal.

According to the present invention, the shielding gas can be introduced as appropriate, and the control rod drive device housing can be easily welded.

FIG. 1 is a schematic view of a nuclear reactor equipped with a control rod driving device. FIG. 2 is a cross-sectional view of a main part of the control rod driving device. FIG. 3 is a partial cross-sectional view of the control rod drive housing. FIG. 4 is a partially enlarged cross-sectional view of the control rod drive device housing. FIG. 5 is a plan view of the welding jig according to the embodiment of the present invention. FIG. 6 is an AA cross-sectional enlarged view of FIG. FIG. 7 is an enlarged cross-sectional view taken along the line BB in FIG. FIG. 8 is a bottom view of the welding jig according to the embodiment of the present invention. FIG. 9 is a plan view of an open state of the welding jig according to the embodiment of the present invention. FIG. 10 is a plan view of the welding apparatus according to the embodiment of the present invention. FIG. 11 is a plan view in which a welding jig is attached to the welding apparatus according to the embodiment of the present invention. FIG. 12 is a front view in which a welding jig is attached to the welding apparatus according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. 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.

FIG. 1 is a schematic view of a nuclear reactor equipped with a control rod driving device. In the following description, the upper part in the installation state when the reactor 100 is used will be referred to as the upper part in each part, and the lower part in the installation state during use will be the lower part in each part. A nuclear reactor 100 shown in FIG. 1 is a pressurized water reactor (PWR) in which a path for extracting energy is separated into a primary cooling system and a secondary cooling system. An outline of a nuclear power plant in which a pressurized water reactor is used will be explained. In a pressurized water reactor, light water (coolant) is used as a reactor coolant and a neutron moderator. By providing a pressurizer (not shown) in the system, in the primary cooling system, light water is converted into high-temperature and high-pressure water that does not boil over the entire core. In the primary cooling system, high-temperature high-pressure water is sent to a steam generator (not shown) that exchanges heat with the secondary cooling system, and heat exchange with light water circulating through the secondary cooling system is performed. . In the secondary cooling system, steam is generated by this heat exchange, and the generated steam is sent to a turbine generator (not shown), thereby generating power with the turbine generator.

Thus, in the reactor 100 according to the present embodiment provided as a pressurized water reactor, the reactor vessel 101 provided as a pressure vessel has a reactor vessel main body 102 so that the internal structure can be inserted therein. And a reactor vessel lid 103 that is mounted on the upper portion of the reactor vessel body 102 and can be opened and closed with respect to the reactor vessel body 102. Among these, the reactor vessel main body 102 is formed in a substantially cylindrical shape with an upper portion opened in the vertical direction when the reactor 100 is installed and a lower portion closed in a spherical shape. Further, the reactor vessel main body 102 is formed with an inlet nozzle 104 and an outlet nozzle 105 for supplying and discharging light water as primary cooling water, which is cooling water used in the primary cooling system, in the vicinity of the upper end side which is an end portion on the opening side. Yes.

In the reactor vessel body 102, a core tank 110 formed in a substantially cylindrical shape is provided below the inlet nozzle 104 and the outlet nozzle 105. The reactor core 110 is formed in a substantially cylindrical shape, has a predetermined gap with the inner surface of the reactor vessel main body 102, and is provided so that the central axis coincides with the cylindrical shape of the reactor vessel main body 102. ing.

In the reactor vessel main body 102, the upper portion of the core tank 110 is connected to the upper core plate 111. The upper core plate 111 is formed in a disk shape and is formed with a large number of communication holes (not shown) passing therethrough, and is provided horizontally in the reactor vessel main body 102. The lower part of the core tank 110 is connected to the lower core plate 112. The lower core plate 112 is formed in a disk shape like the upper core plate 111 and has a large number of communication holes (not shown) penetrating through it. The lower core plate 112 is provided horizontally in the reactor vessel body 102. Yes.

In the reactor vessel main body 102, an upper core support plate 113 is fixed above the core tank 110. The upper core support plate 113 is provided by suspending a plurality of core support rods 114, and the upper core plate 111 is suspended and supported via the core support rod 114. That is, when the upper core plate 111 is suspended and supported by the upper core support plate 113 via the core support rod 114, the core tank 110 connected to the upper core plate 111 is also suspended and supported by the upper core support plate 113. ing. On the other hand, the lower core plate 112 is positioned and held with respect to the inner surface of the reactor vessel main body 102 by a plurality of radial keys 115. Positioned and held with respect to the inner surface.

The core 120 is formed by the core tank 110, the upper core plate 111, and the lower core plate 112 thus provided. A large number of fuel assemblies 121 are arranged in the core 120. The fuel assembly 121 is configured by bundling a large number of fuel rods in a lattice pattern by a support lattice. The fuel assembly 121 is configured such that the control rod 122 can be inserted. A plurality of upper ends of the control rod 122 are combined into a control rod cluster 123. The upper core plate 111 is supported by a number of control rod cluster guide tubes 124 that penetrate the upper core support plate 113. The control rod cluster guide tube 124 guides the control rod cluster 123, and an upper end portion that penetrates the reactor vessel lid 103 extends to the control rod driving device 125. A control rod cluster drive shaft 140, which will be described later, extended from the control rod drive device 125 is connected to the control rod cluster 123 through the control rod cluster guide tube 124 and extended to the fuel assembly 121. Although not shown, the upper core support plate 113 supports a large number of in-core instrumentation guide tubes that penetrate the upper core support plate 113. The in-core instrumentation guide tube has a lower end extending to the fuel assembly 121, and is provided so that a sensor capable of measuring a neutron flux can be inserted into the fuel assembly 121.

In the reactor vessel main body 102, a portion located above the core 120 and communicating with the outlet nozzle 105 is formed as an upper plenum 131. On the other hand, a hemispherical space located below the core 120 and formed by the lower core plate 112 and the inner surface of the spherically closed portion below the reactor vessel body 102 is formed as a lower plenum 132. Has been. Further, a portion formed between the reactor vessel main body 102 and the reactor core 110 and communicating with the inlet nozzle 104 and the lower plenum 132 is formed as a downcomer portion 133. The upper plenum 131 is formed by being partitioned by the core tank 110, the upper core support plate 113, and the upper core plate 111. The upper plenum 131 communicates with the outlet nozzle 105 and includes a number of communication holes formed in the upper core plate 111. Via the core 120. The lower plenum 132 is formed by being divided by a lower core plate 112 that is the bottom of the reactor core 110 and the reactor vessel main body 102, and is connected to the core 120 through a number of communication holes formed in the lower core plate 112. Communicate. The downcomer portion 133 is formed by being partitioned by the reactor vessel main body 102 and the side wall of the reactor core 110, and the upper portion communicates with the inlet nozzle 104 and the lower portion communicates with the lower plenum 132.

When operating the nuclear reactor 100 configured as described above, uranium contained in the fuel assembly 121 as a fuel constituting the fuel assembly 121 while circulating light water used as a coolant or a neutron moderator. Fission reaction is performed on fissile materials such as 235 and plutonium. When a fission reaction is performed on the fissile material, the amount of control rod 122 inserted into the fuel assembly 121 is adjusted by a control rod driving device 125 provided in the reactor vessel lid 103. Thereby, the fission reaction in the core 120 is controlled. When the fissile material undergoes fission, thermal energy is generated. However, since the surroundings of the fuel assembly 121 are filled with circulating light water, the thermal energy is transmitted to the light water around the fuel assembly 121. Thereby, the light water filled in the reactor vessel 101 is heated. Thus, the high-temperature light water heated by the thermal energy generated during the fission reaction is discharged from the outlet nozzle 105 and sent to the steam generator.

That is, when the fissile material contained in the fuel assembly 121 is fissioned, neutrons are released, and light water used as cooling water for the moderator and the primary cooling system is converted into the kinetic energy of the released fast neutrons. Is reduced to thermal neutrons, facilitating new fission, and taking away the generated heat and cooling.

Also, the control rod 122 is provided so that the number of neutrons generated in the core 120 can be adjusted by absorbing neutrons released during the fission of the fissile material. For example, when the insertion amount of the control rod 122 into the fuel assembly 121 is increased, the amount of neutrons absorbed by the control rod 122 is increased, so that the amount of neutrons that fission the fissionable material is decreased. On the other hand, when the control rod 122 is moved in the pulling direction and the insertion amount of the control rod 122 into the fuel assembly 121 is reduced, the amount of neutrons absorbed by the control rod 122 is reduced. Increases the amount of neutrons that cause fission. As a result, the frequency at which the fissile material undergoes fission can be changed. Therefore, during operation of the nuclear reactor 100, the fission reaction is controlled by adjusting the amount of insertion of the control rod 122, and the heat generated by the fission reaction. Adjust the amount of energy.

During operation of the reactor 100, light water is circulated in the primary cooling system. This light water flows into the reactor vessel body 102 from the inlet nozzle 104, and the downcomer portion 133 communicating with the inlet nozzle 104 faces downward. It flows down and reaches the lower plenum 132, and the flow direction is changed upward by the spherical inner surface of the lower plenum 132. As a result, the light water rises from the lower plenum 132, passes through the communication hole of the lower core plate 112, and then flows into the core 120. The light water that has flowed into the core 120 cools the fuel assembly 121 by absorbing thermal energy generated from the fuel assembly 121 disposed in the core 120. On the other hand, the temperature rises to the upper core plate 111 at a high temperature. The high-temperature light water that has reached the upper core plate 111 passes through the communication hole of the upper core plate 111, rises to the upper plenum 131, and is discharged from the reactor vessel body 102 through the outlet nozzle 105.

FIG. 2 is a cross-sectional view of the main part of the control rod driving device. As shown in FIG. 2, the control rod cluster drive shaft 140 of the control rod drive device 125 is provided so as to be movable in the axial direction (longitudinal direction) in a drive shaft housing 161 described later. The control rod cluster drive shaft 140 has a plurality of circumferential grooves 140a formed on the surface thereof at equal pitches in the longitudinal direction (vertical direction). Further, the control rod driving device 125 is provided with a holding mechanism 146. The holding mechanism 146 drives a fixed grip latch 142 provided in one of the circumferential grooves 140 a of the control rod cluster drive shaft 140 so as to be disengageable, and drives the fixed grip latch 142 via a latch link 143 and a plunger 144. The control rod cluster drive shaft 140 is held by engaging the fixed grip latch 142 with the circumferential groove 140a. In addition, the control rod driving device 125 is provided with a driving mechanism 152. The drive mechanism 152 drives a movable grip latch 147 provided in one of the circumferential grooves 140 a of the control rod cluster drive shaft 140 so as to be able to be engaged and disengaged, and drives the movable grip latch 147 via a latch link 148 and a plunger 149. The movable gripping coil 150 and the raising coil 151 for moving the latch link 148 and the plunger 149 in the vertical direction are provided to move the control rod cluster drive shaft 140 up and down.

In FIG. 2, reference numeral 153 is a fixed handle magnetic pole that is excited by the fixed grip coil 145, reference numeral 154 is a movable handle magnetic pole that is excited by the movable grip coil 150, and reference numeral 155 is a lift that is excited by the raising coil 151. It is a magnetic pole. Reference numerals 156a to 156c denote return springs.

The fixed handle magnetic pole 153 is demagnetized by the fixed grip coil 145, and the fixed grip latch 142 is separated from the circumferential groove 140a of the control rod cluster drive shaft 140. On the other hand, when the movable handle magnetic pole 154 is excited by the movable gripping coil 150 and the movable gripping latch 147 is engaged with the circumferential groove 140a of the control rod cluster drive shaft 140, when the lifting magnetic pole 155 is excited by the lifting coil 151, the movable gripping magnetic pole 154 is movable. The handle magnetic pole 154 and the movable grip latch 147 are attracted to the raised magnetic pole 155 against the urging force of the return spring 156a together with the movable grip coil 150, and the control rod cluster drive shaft 140 is lifted by one pitch of the circumferential groove 140a. it can.

Next, after the fixed handle magnetic pole 153 is excited by the fixed grip coil 145 and the fixed grip latch 142 is engaged with the circumferential groove 140a of the control rod cluster drive shaft 140, the movable handle magnetic pole 154 is demagnetized by the movable grip coil 150. When the raising magnetic pole 155 is demagnetized by the raising coil 151, the movable gripping latch 147 is separated from the circumferential groove 140a of the control rod cluster driving shaft 140, and the movable handle magnetic pole 154 and the movable gripping latch are latched by the urging force of the return spring 156a. 147 can be lowered with the movable gripping coil 150.

Then, after the movable gripping magnetic pole 154 is excited by the movable gripping coil 150 and the movable gripping latch 147 is engaged with the circumferential groove 140a of the control rod cluster drive shaft 140, the stationary gripping magnetic pole 153 is demagnetized by the stationary gripping coil 145. The control rod cluster drive shaft 140 can be raised to a predetermined pitch by repeating the above-described operation from the state in which the fixed grip latch 142 is separated from the circumferential groove 140a of the control rod cluster drive shaft 140. In order to lower the control rod cluster drive shaft 140, the reverse operation of the above-described operation may be performed.

3 is a partial cross-sectional view of the control rod drive device housing, and FIG. 4 is a partially enlarged cross-sectional view of the control rod drive device housing. The control rod drive device housing 160 is formed in a cylindrical shape, and as shown in FIG. 1, surrounds the drive shaft housing 161 that houses the control rod cluster drive shaft 140 described above and a part of the outer periphery of the drive shaft housing 161. The latch housing 162 includes the holding mechanism 146 and the drive mechanism 152 described above, and a cap 163 that closes the upper end of the drive shaft housing 161. Further, the lower end of the latch housing 162 is connected to a cylindrical nozzle 164 that is welded through the reactor vessel lid 103. The drive shaft housing 161 is inserted from the upper end of the latch housing 162 and connected to the latch housing 162. Then, assuming that the control rod cluster drive shaft 140 has failed, in order to take out the control rod cluster drive shaft 140, the nozzle 164, the latch housing 162, the latch housing 162, the drive shaft housing 161, the drive shaft housing 161, and the cap 163 are detachably connected to each other by screw connection. FIG. 3 shows a portion where the nozzle 164 and the latch housing 162 are connected. Further, since the inside of the control rod drive device housing 160 communicates with the high-temperature and high-pressure coolant space in the reactor vessel lid 103, it is considered that the coolant leaks along the screw surface, and therefore, as shown in FIG. As described above, the outer end side 165 a of the thread surface 165 is closed by circumferential seal welding called a canopy seal 166. As shown in FIG. 4, the canopy seal 166 has a dome-shaped cross section, has little change in the cross-sectional shape of the welded portion 167, and suitably seals the high pressure of the coolant that propagates through the thread surface 165 (see FIG. 3). In addition, cutting at the time of decomposition is easy.

Referring to the control rod drive device housing 160 described above, a welding jig and a welding device used when welding the canopy seal 166 of the control rod drive device housing 160 will be described below.

First, the welding jig will be described. FIG. 5 is a plan view of the welding jig according to the present embodiment, FIG. 6 is an enlarged sectional view taken along the line AA in FIG. 5, and FIG. 7 is an enlarged sectional view taken along the line BB in FIG. 8 is a bottom view of the welding jig, and FIG. 9 is a plan view of the welding jig in an open state.

As shown in FIGS. 5 to 9, the welding jig 1 includes a jig body 2, a gas introduction part 3, a welding torch placement part 4, a guide part 5, a mounting part 6, and an opening / closing part 7. I have.

As shown in FIG. 5, the jig body 2 is formed in an annular shape along the circumference of the canopy seal 166 so as to surround the canopy seal 166. As shown in FIGS. 6 and 7, the jig body 2 has a concave portion 2 a that forms a predetermined space toward the groove portion 166 a of the canopy seal 166 on the inner peripheral surface.

The gas introduction part 3 is provided in the jig body 2. As shown in FIG. 6, the gas introduction part 3 has an introduction port 3 a outside the annular shape of the jig body 2, and has a discharge port 3 b in the recess 2 a of the jig body 2. It is provided through the inside. Specifically, the gas introduction part 3 has an introduction pipe 3 c that is fitted in the recess 2 a so as to follow the annular shape of the jig body 2. The introduction pipe 3c is formed with both ends closed. In the introduction pipe 3c, a plurality of discharge ports 3b are provided at predetermined intervals along the annular shape of the jig body 2 on the side facing the recess 2a. In addition, the jig body 2 is formed with an introduction passage 3d that opens into the introduction pipe 3c from the outside of the annular shape. A portion where the introduction passage 3d opens to the outside of the annular shape of the jig body 2 is formed as an introduction port 3a. In the present embodiment, the introduction passage 3d is extended to the outside of the jig body 2 via the extension pipe 3e welded and fixed to the outside of the annular shape of the jig body 2, and is extended to the extended end of the extension pipe 3e. An opening portion of the attached coupler 3f is configured as an introduction port 3a. The coupler 3f is connected to a gas supply hose (not shown) for supplying a shielding gas. In the present embodiment, the jig body 2 is divided into two parts, and the gas introduction part 3 is provided in each of the divided parts of the jig body 2.

As shown in FIG. 5, the welding torch arrangement portion 4 is a portion formed by cutting out a part of the jig body 2 and opening the annular outer side and the inner side of the jig body 2. . That is, in the welding torch arrangement portion 4, a welding torch 15 of the welding apparatus 10 to be described later is arranged from the annular outer side of the jig main body 2 toward the inner side of the annular ring, whereby the welding torch 15 is connected to the canopy seal 166. It is the part comprised so that it could approach to the groove part 166a.

The guide part 5 is provided on the jig body 2. As shown in FIG. 7, the guide portion 5 is for contacting the control rod drive device housing 160 and holding the concave portion 2 a of the jig main body 2 at a position facing the groove portion 166 a of the canopy seal 166. . Specifically, the guide portion 5 is attached to a base member 5a fixed to the upper surface of the jig body 2 so that the roller 5b can rotate about the shaft 5c, and the roller 5d can rotate about the shaft 5e. It is attached. The roller 5b is provided so as to be rotatable about a shaft 5c extending in an annular radial direction in the jig body 2. The roller 5b contacts the outer surface facing downward of the latch housing 162 at the portion of the canopy seal 166 to which the nozzle 164 and the latch housing 162 are connected, so that the roller 5b is cured at the vertical position facing the groove portion 166a of the canopy seal 166. While holding the recess 2a of the tool body 2, the tool body 2 rotates to guide the movement of the jig body 2 along the circumference of the canopy seal 166. The roller 5d is provided to be rotatable around a shaft 5e orthogonal to the annular radial direction in the jig body 2. The roller 5d is in a radial position facing the groove portion 166a of the canopy seal 166 by contacting the outer surface of the latch housing 162 that faces the outside of the diameter in the canopy seal 166 portion where the nozzle 164 and the latch housing 162 are connected. The concave portion 2a of the jig main body 2 is held by the rotation of the jig main body 2 and the movement of the jig main body 2 along the circumference of the canopy seal 166 is guided. A plurality of guide portions 5 are provided around the annular shape of the jig body 2 (four in the present embodiment), and two guide parts 5 are provided for each of the divided jig bodies 2.

The attachment portion 6 is a portion to which a support rod 13a (see FIG. 12) as a welding jig support portion 13 to be described later that supports the jig body 2 is attached to a welding apparatus 10 to be described later. Specifically, as shown in FIGS. 5 and 8, the mounting portion 6 has a female screw hole 6a facing downward that a male screw portion provided at the tip (upper end) of the support bar 13a shown in FIG. Is formed. A plurality (two in the present embodiment) of the attachment parts 6 are provided around the annular shape of the jig body 2, and one is provided for each of the divided parts of the jig body 2.

The opening / closing part 7 opens and closes the annular shape of the jig body 2. As shown in FIGS. 5 and 9, the opening / closing portion 7 has the notch portion that forms the welding torch placement portion 4 as a leading end, and the jig body 2 that has the opposite side in the diameter direction of the welding torch placement portion 4 as a base end. Divided into two. Then, the opening / closing part 7 connects the divided base ends of the jig body 2 with the shafts 7a, so that each of the divided parts of the jig body 2 is connected to the welding torch placement part 4 as shown in FIG. The ring is configured to open. When the jig main body 2 is opened, the opening is larger than the diameter of the canopy seal 166 portion. Further, the opening / closing portion 7 is provided with a torsion coil spring 7b around the shaft 7a, and each end portion of the torsion coil spring 7b is fixed to each of the divided parts of the jig body 2, whereby the torsion coil spring 7b is elastic. As shown in FIG. 5, the divided parts of the jig body 2 are closed to maintain an annular shape.

As described above, the welding jig 1 according to the present embodiment is for welding the canopy seal 166 provided circumferentially in the control rod drive device housing 160 formed in a cylindrical shape along the circumference. The jig body 2 is formed in an annular shape along the circumference of the canopy seal 166, and the inner peripheral surface thereof is disposed toward the groove portion 166 a of the canopy seal 166. A gas introduction part 3 having an introduction port 3a and having a discharge port 3b on the inner peripheral surface of the jig body 2 and penetrating the inside of the jig body 2, and a part of the jig body 2 are cut out. The welding torch disposition portion 4 that opens the annular outer side and the inner side of the jig main body 2 and the control rod drive device housing 160 provided on the jig main body 2 so as to contact the inner peripheral surface of the jig main body 2 canopy Position facing the groove portion 166a of the seal 166 As a and a guide portion 5 for holding the jig main body 2.

According to this welding jig 1, a welding torch is supplied while supplying a shielding gas (for example, argon gas) from the introduction port 3 a of the gas introduction unit 3 and rotating the jig body 2 along the circumference of the canopy seal 166. The groove portion 166a of the canopy seal 166 is TIG welded with the welding torch 15 arranged at the position of the arrangement portion 4. Thereby, it becomes possible to introduce the shield gas at the time of TIG welding appropriately into the groove portion 166a, and to easily perform TIG welding along the circumference of the canopy seal 166.

The welding jig 1 of the present embodiment further includes an opening / closing part 7 that opens and closes the annular shape of the jig body 2.

According to this welding jig 1, the jig body 2 can be easily mounted around the cylindrical control rod drive device housing 160 by opening the annular shape of the jig body 2 by the opening / closing part 7. Become.

Next, the welding apparatus will be described. FIG. 10 is a plan view of the welding apparatus according to the present embodiment, FIG. 11 is a plan view of the welding apparatus attached to the welding apparatus, and FIG. 12 is a front view of the welding apparatus attached to the welding apparatus. FIG.

As shown in FIGS. 10 to 12, the welding apparatus 10 includes a fixed portion 11, a rotating portion 12, a welding jig support portion 13, and a welding torch support portion 14.

The fixing portion 11 has a fixing portion main body 11a formed in a cylindrical shape so as to follow the circumference of the nozzle 164 to which the lower end of the latch housing 162 of the control rod driving device housing 160 is connected. Moreover, the fixing | fixed part 11 has the chuck | zipper part 11b provided so that advance / retreat was possible inside the cylindrical shape of the fixing | fixed part main body 11a. For example, the chuck portion 11b moves back and forth inside the fixed portion main body 11a by supplying air to an air cylinder (not shown). And the chuck | zipper part 11b contact | abuts to the outer peripheral surface of the nozzle 164, when it advances inside the fixing | fixed part main body 11a. Thereby, the fixing | fixed part 11 is fixed to the said nozzle 164 so that the nozzle 164 may be held. On the other hand, the chuck portion 11b is separated from the outer peripheral surface of the nozzle 164 when retracted from the inside of the fixed portion main body 11a. Thereby, the fixing part 11 is released from fixing to the nozzle 164. A plurality (four in this embodiment) of chuck portions 11b are provided along the circumference of the fixed portion main body 11a. Further, the fixed portion 11 is integrally provided on the outer periphery of the fixed portion main body 11a with a cylindrical fixed frame 11c with the bottom portion connected to the fixed portion main body 11a.

The rotating part 12 is provided between the fixed part main body 11a and the fixed frame 11c in the fixed part 11 so as to be rotatable around the fixed part main body 11a. The rotating part 12 has a rotating disk 12a formed in an annular shape so as to surround the fixed part main body 11a. The turntable 12a is rotatably supported on an annular rail (not shown) provided between the fixed portion main body 11a and the fixed frame 11c on the lower side. The rotating unit 12 has a drive unit 12b. The drive unit 12b is a motor fixed to the fixed frame 11c, and provides power for rotating the turntable 12a. Moreover, the drive part 12b can control the rotation angle of the turntable 12a by using a pulse motor or the like.

The welding jig support part 13 supports the welding jig 1 mentioned above. As shown in FIG. 12, the welding jig support portion 13 includes a support bar 13a and a fixed base portion 13b. The support rod 13a is provided with a male screw portion that is screwed into the female screw hole 6a of the attachment portion 6 of the welding jig 1 at the tip (upper end) thereof. The fixed base portion 13b is fixed to the rotating disk 12a of the rotating portion 12, and the base end (lower end) of the support bar 13a is inserted and fixed with a screw 13c. That is, the welding jig support part 13 supports the welding jig 1 with respect to the turntable 12a of the rotating part 12 via the support bar 13a. Moreover, the welding jig support part 13 changes the screwing depth of the support rod 13a screwed into the female screw hole 6a of the attachment part 6 in the welding jig 1, thereby increasing the height at which the welding jig 1 is supported. adjust. Thereby, the welding jig support part 13 supports the welding jig 1 at the position of the groove part 166a of the canopy seal 166. In the welding jig support portion 13, a plurality of support rods 13 a, a fixed base portion 13 b, and screws 13 c are provided (two in the present embodiment) corresponding to the attachment portion 6 of the welding jig 1.

The welding torch support part 14 supports the welding torch 15. The welding torch support portion 14 has a fixing base 14a to which the welding torch 15 is fixed. Moreover, the welding torch support part 14 has the rail 14b fixed to the turntable 12a so that it may extend toward the rotation center of the turntable 12a. A moving plate 14c is provided on the rail 14b so as to be movable in the extending direction of the rail 14b. The movable plate 14c and the fixed base 14a are connected to each other via a drive mechanism 14d including a motor and a gear box that transmits the drive of the motor. The drive mechanism 14d provides a driving force for moving the moving plate 14c along the rail 14b. That is, the welding torch support part 14 supports the welding torch 15 with respect to the rotating disk 12a of the rotating part 12 via the fixed base 14a, the rail 14b, the moving plate 14c, and the drive mechanism 14d. Further, the welding torch support portion 14 moves the welding torch 15 closer to or away from the groove portion 166a of the canopy seal 166 by driving of the drive mechanism 14d. Thereby, the welding torch support part 14 arrange | positions the welding torch 15 with respect to the welding torch arrangement | positioning part 4 of the welding jig 1 supported by the welding jig support part 13. FIG.

In addition, the welding apparatus 10 is configured so that the fixed portion 11 and the rotating portion 12 can open and close the annular shape. The fixed part 11 and the rotating part 12 are divided into two parts, and one end of each of the divided parts is connected by a shaft 16. Thereby, each divided | segmented other end opens. When the fixed portion 11 and the rotating portion 12 are opened, the opening of the fixed portion 11 is larger than the diameter of the nozzle 164 portion. This makes it possible to easily mount the welding device 10 around the cylindrical control rod drive device housing 160. Further, although not shown in the figure, the closed state of the fixed portion 11 and the rotating portion 12 is held by the lock mechanism.

Moreover, the welding apparatus 10 has a wire feed mechanism 17 for feeding a welding wire 18 to the welding torch 15 as shown in FIGS. 10 and 11. The wire feed mechanism 17 is attached to the turntable 12a of the rotary unit 12, and includes a wire reel 17a around which the welding wire 18 is wound, a wire feeder 17b that feeds the welding wire 18 wound around the wire reel 17a, and a wire feeder 17b. And a wire guide 17c that guides the welding wire 18 fed out to the position of the welding torch 15. Also, a flexible tube 17d extending from the wire guide 17c to the welding torch 15 is provided between the wire guide 17c and the welding torch 15 so that the welding wire 18 can be smoothly fed to the welding torch 15 without bending. It has been. The distal end of the tube 17 d is supported by the moving plate 14 c of the welding torch support portion 14 described above, and is provided so as to be movable together with the welding torch 15.

Moreover, the welding apparatus 10 has the imaging | photography means 19 as shown in FIG.10 and FIG.11. The photographing means 19 is, for example, a CCD (Charge Coupled Device) image sensor, and photographs the periphery of the welding torch 15. The photographing means 19 is supported by the moving plate 14 c of the welding torch support portion 14 described above, and is provided so as to be movable together with the welding torch 15.

Moreover, the welding apparatus 10 has the illumination means 20, as shown in FIG.10 and FIG.11. The illumination means 20 illuminates the vicinity of the welding torch 15. The illumination means 20 is attached to the turntable 12a of the rotating unit 12, and in the present embodiment, includes a light source unit 20a and a reflecting unit 20b. The light source unit 20a emits light. The reflection part 20b reflects the light irradiated by the light source part 20a toward the periphery of the welding torch 15. In addition, if the light source part 20a can irradiate light around the welding torch 15 directly, it is not necessary to provide the reflection part 20b.

Such a welding apparatus 10 is configured to drive the chuck portion 11b in the fixed portion 11, drive the rotating plate 12a in the rotating portion 12 (drive the driving portion 12b), and drive the moving plate 14c in the welding torch support portion 14 (driving mechanism 14d). Driving of the welding torch 15, driving of the wire feeder 17b in the wire feed mechanism 17, driving of the photographing means 19, driving of the light source part 20a in the illumination means 20, and coupler 3f of the gas introduction part 3 in the welding jig 1. The supply of shield gas to the gas supply hose connected to is collectively controlled by a control means (not shown).

In order to perform welding of the canopy seal 166 by the welding apparatus 10 described above, the nozzle 164 is passed by opening / closing the opening / closing part 7 in a state where the fixing part 11 and the rotating part 12 are opened and closed and attached to the nozzle 164. The welding jig 1 is attached to the welding jig support portion 13. Here, the height position of the welding jig 1 is adjusted by the welding jig support section 13 so that the positions of the welding torch placement section 4 and the welding torch 15 of the welding jig 1 are matched. Next, the welding apparatus 10 is moved upward so that the inner peripheral surface of the jig main body 2 in the welding jig 1 faces the groove portion 166 a of the canopy seal 166, and the welding device 10 is moved by the fixing portion 11. Is fixed to the nozzle 164. Next, a shielding gas (for example, argon gas) is supplied to the welding jig 1, a voltage is applied to the electrode of the welding torch 15, and the rotating unit 12 is rotated. Accordingly, the groove portion 166a of the canopy seal 166 can be TIG welded while supplying the shielding gas along the circumference of the canopy seal 166.

As described above, the welding apparatus 10 according to the present embodiment is for welding the canopy seal 166 provided circumferentially in the control rod drive device housing 160 formed in a cylindrical shape along the circumference. The fixed portion 11 fixed to the nozzle 164 of the control rod driving device housing 160, the rotating portion 12 provided in the fixing portion 11 in a manner of rotating around the control rod driving device housing 160, and the rotating portion 12. The welding jig 1 is supported at the position of the groove portion 166a of the canopy seal 166, and the welding torch arrangement portion 4 of the welding jig 1 is welded to the rotating jig 12. And a welding torch support portion 14 on which the torch 15 is disposed.

According to this welding apparatus 10, the welding jig 1 is attached to the welding jig support portion 13 and the welding apparatus 10 is fixed to the nozzle 164 by the fixing portion 11. Gas), a voltage is applied to the electrode of the welding torch 15, and the rotating portion 12 is rotated so that the groove portion 166a of the canopy seal 166 is supplied while supplying the shielding gas along the circumference of the canopy seal 166. Can be welded. As a result, shield gas during TIG welding can be appropriately introduced into the groove portion 166a, and TIG welding can be easily performed along the circumference of the canopy seal 166.

In addition, although the welding jig 1 and the welding apparatus 10 mentioned above are forms corresponding to the canopy seal 166 to which the nozzle 164 and the latch housing 162 are connected, the latch housing 162 and the drive shaft housing 161 are also connected. For the canopy seal and the canopy seal to which the drive shaft housing 161 and the cap 163 are connected, a shielding gas is appropriately introduced and TIG welding is easily performed with the same configuration although some shape changes are required. It is possible.

DESCRIPTION OF SYMBOLS 1 Welding jig 2 Jig body 3 Gas introduction part 3a Inlet 3b Ejection port 4 Welding torch arrangement part 5 Guide part 6 Mounting part 7 Opening and closing part 10 Welding device 11 Fixing part 12 Rotating part 13 Welding jig support part 14 Welding torch Support portion 15 Welding torch 16 Shaft 17 Wire feed mechanism 18 Welding wire 160 Control rod drive device housing 166 Canopy seal 166a Groove

Claims

A welding jig for a control rod drive device housing for welding a canopy seal provided circumferentially in a control rod drive device housing formed in a cylindrical shape along the circumference,
A jig body that is formed in an annular shape along the circumference of the canopy seal, and has an inner circumferential surface disposed toward a groove portion of the canopy seal,
A gas introduction part that has an introduction port on the outer side of the annular shape of the jig body and has a discharge port on the inner peripheral surface side of the jig body and penetrates the inside of the jig body;
A welding torch arrangement portion that is formed by cutting a part of the jig body and opens the annular outer side and the inner side of the jig body;
A guide that is provided on the jig body and holds the jig body so that the inner peripheral surface of the jig body faces the groove portion of the canopy seal by contacting the control rod drive device housing. And
A welding jig for a control rod drive device housing.
The welding jig for a control rod drive device housing according to claim 1, further comprising an opening / closing part for opening / closing an annular shape of the jig body.
A control rod drive device welding apparatus for welding a canopy seal provided circumferentially in a control rod drive device housing formed in a cylindrical shape along the circumference,
A fixing portion fixed to the control rod drive device housing;
A rotating part provided in the fixed part in a manner of rotating around the control rod drive device housing;
A welding jig support part that is provided in the rotating part and supports the welding jig according to claim 1 or 2 at a position of a groove part of the canopy seal;
A welding torch support portion that is provided in the rotating portion and arranges a welding torch in a welding torch arrangement portion of the welding jig;
A welding apparatus for a control rod drive device housing.