JP2583434Y2 - Laser repair equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser repairing device capable of repairing a narrow portion such as in a valve seat, and more particularly to a laser repairing device suitable for repairing a defect generated in a hardened portion of a valve for a plant piping valve. Things.

[0002]

2. Description of the Related Art Conventionally, in industrial facilities such as a nuclear power plant, a large number of large-sized pipes and associated large-sized valves for piping have been used. The valve seat of such a large pipe valve is hardened with a material such as stellite in order to increase the wear resistance of a sliding portion between the valve body and the valve body.

[0003] However, in a built-up portion on which such a treatment is performed, a defect such as a crack may occur due to long-term use. In this case, as an appropriate repair work method of the defective portion, a repair method in the field or a work method of replacing the valve seat with a new one is generally used.

[0004]

As described above, a hardfacing process is performed on a valve seat of a large pipe valve, and repair work for cracks in the hardfacing portion is required. However, since the valve seat has an integral welded structure to the valve box, it is difficult to remove the valve seat from the valve box. There was also a problem that there was a risk of exposure to radiation by the elderly. Therefore, workability is poor, and a repair method using an appropriate repair device has been required.

[0005] On the other hand, for those which are severely cracked, there is no effective repair method, and the valve seat is replaced with a new one, so that not only the workability is poor but also the cost is excessive.

[0006]

According to a first aspect of the present invention, there is provided a laser repair apparatus, comprising: a support arm detachably mounted on a flange surface of a valve and fixed to the valve; A laser torch that is rotatably held and emits a laser beam from the distal end side, and is interposed between the support arm and the laser torch and along a radial direction of rotation around the base end side of the laser torch. A radial axis that allows the laser torch to move, a front-rear axis that is interposed between the support arm and the laser torch, and that enables the laser torch to move along the axial direction of the pivot axis, and that is connected to the support arm; And a controller for remotely controlling the radial axis, the front-rear axis, and the turning axis to repair a defect generated in the valve seat of the valve.

A laser repairing device according to a second aspect of the present invention selectively supplies or stops supply of metal powder while being controlled by a control device together with a laser beam emitted from a laser torch, and supplies the metal powder. The present invention is characterized in that it has a powder feeding nozzle capable of performing a repair and a melt repair performed by stopping the supply of the metal powder.

[0008]

The laser beam is emitted from the laser torch held by the support arm, and the defect generated in the valve seat is repaired by the laser beam.

At this time, the control device controls the rotation position of the laser torch about the rotation axis, the axial position of the laser torch along the axial direction of the radial axis, and the axial position of the laser torch along the axial direction of the front-rear axis. While the laser torch is being moved, the repair work is performed.

[0010] In addition, along with the repair, by supplying metal powder from the powder feed nozzle, the overlay is repaired,
Melt repair is performed by stopping the supply of metal powder from the powder feed nozzle.

[0011]

1 to 8 show a laser repair apparatus according to an embodiment of the present invention, and the embodiment will be described with reference to these drawings. The work will be explained through the case of repairing valves for nuclear power plants.

FIG. 1 is a front view of the laser repair apparatus according to the present embodiment, FIG. 2 is an enlarged plan view of the tip of the laser repair apparatus, and FIG. 4 is FIG.
5 is a sectional view taken along the line AA, and FIG. 5 is a sectional view taken along the line CC in FIG.

As shown in FIG. 1, a support arm 6 serving as a mounting portion of a device 40 according to the present embodiment is structured to be mounted on a flange surface 8a of a gate valve 8 used for piping in a nuclear power plant. . That is, it is detachably attached to the gate valve 8 via the dedicated base plate 1, support bracket 2 and guide holder 3, and is fixed. The support arm 6 is supported so as to be attached to the distal end side of the insertion shaft 4, and its vertical position is adjusted by rotating a push bolt 5 screwed into the insertion shaft 4.

Further, the support arm 6 includes
The laser repair head 7 is located at a position corresponding to the hardened portion 9a of the valve seat, which is the tip of the laser repair head, which is shown in an enlarged manner in FIGS. As shown in these figures, a base end side of an angle type laser torch 19 is rotatably held by a support arm 6 via a turning shaft 12 which is turned by a turning drive motor 10. Further, the laser torch 19 is interposed between the support arm 6 and the laser torch 19 so as to be parallel to the laser torch 19, and can be moved in the radial direction of the rotation of the turning shaft 12 about the base end side of the laser torch 19 as the center of rotation. Is set. Further, the pivot 12
A front / rear shaft 25 is provided between the support arm 6 and the laser torch so as to be positioned inside the laser torch 19 so as to move the laser torch 19 along the axial direction of the turning shaft 12.

Accordingly, the laser repair head 7 is composed of the radial shaft 11, the turning shaft 12, the front and rear shafts 25 supporting the laser torch 19, and the cable winding reel 21 of the cables necessary for turning the turning shaft 12. It is held by a support arm 6. An optical fiber 17 of a YAG laser is connected to an entrance of the laser torch 19, and is rotatably supported via a bearing 20 for preventing the optical fiber 17 from being twisted.

A guide cylinder 22 which forms the outer frame of the laser torch 19 and extends in the radial direction of the turning shaft 12 around the base end of the laser torch 19 has a removable structure. It is possible to replace the guide tube 22 according to the diameter. A laser condensing lens 23 for narrowing a laser beam sent from the optical fiber 17 via the intermediate optical system 18 is provided on an emission portion on the distal end side of the guide cylinder 22.
Mirror 24, visual camera 13 for confirming target position
And a tip block 41 having a built-in miniature halogen lamp 14 or the like as an illumination light, and a powder feeding nozzle 15 for sending metal powder to the emission section, a laser torch 19 and a valve seat attached to the tip block 41. A positioning sensor 16 is provided for keeping a constant distance from the surface 9. Accordingly, the laser light transmitted through the optical fiber 17 and the mirror 24 and the like is
By 3, the light is focused on the repaired portion, and the energy density required for the repair can be obtained.

On the other hand, as shown in FIG. 6 showing the overall configuration of the present apparatus, a control device 26 and a YAG laser oscillator 27
The laser repair head 7 and the control device 26 are connected by a control cable / hose 28 at a place where there is no influence of radioactivity away from the place of the radioactive atmosphere where the gate valve 8 exists. The optical fiber 18 is connected to the YAG laser oscillator 27 to transmit electricity, gas, powder, signal information, laser light, and the like. The optical fiber 17 has a switching mechanism so that a red He-Ne laser can be transmitted as guide light in addition to the YAG laser. Here, the control device 26 includes a monitor unit (not shown) for monitoring a repair target position, a control unit for performing automatic operation control of repair welding, a driver unit for driving each motor, and an empty for powder supply and shield gas supply. Pressure unit.

Next, the operation and operation of the apparatus 40 having the above-described configuration when performing a repair work will be described.

First, before repairing, it is necessary to determine a position to be irradiated with a laser beam. Before repairing, a He—Ne laser is passed through the optical fiber 17 so that a crack is generated. Using a visual camera 13 provided at the tip of the laser repair head 7 by using a radial axis 11, a pivot axis 12 and a visual camera 13 provided at the tip of the laser repair head 7, the irradiation point is set so that the laser light is irradiated on the monitor by a monitor in the control device 26. adjust. With this adjustment,
The repair position can be determined by remote control on the device 40. Further, by using the optical fiber 17, the lens and the mirror system in the tip block 41, and the radial axis 11, the front-rear axis 25, and the turning axis 12, the laser beam is applied to an arbitrary portion in the overlay 9 a of the valve seat surface 29. By transmitting to
The laser beam can be applied to a crack generated at an arbitrary portion of the built-up portion 9a to perform repair.

Incidentally, since the crack may be generated at all points on the valve seat 9, the turning shaft 12 of the laser repair head 7 needs to rotate in the 360-degree direction. At this time, by making the entrance from the optical fiber 17 to the laser torch 19 a rotatable bearing structure, twisting of the optical fiber 17 during repair can be prevented.

When performing laser melting, the relative position (the amount of defocusing) between the focal position of the processing lens 23 and the repair surface is an important processing condition. According to the information from the sensor 16, the longitudinal axis 25
By adjusting the distance, the distance between the valve seat surface 29 and the laser repair head 7 can be controlled to a predetermined constant value, and the condition can be determined accurately.

Next, repair work by the apparatus according to the present embodiment will be specifically described with reference to the drawings.

First, the valve cover of the gate valve 8 to be repaired is removed, and as shown in FIG. 1, the base plate 1, the support bracket 2, and the guide holder 3, which are the guide mechanisms of the present apparatus, are attached thereto. Next, the insertion shaft 4 is inserted into the guide holder 3, and the laser repair head 7 is guided to the valve seat 9. further,
While checking the valve seat surface 29 of the valve seat 9 with the visual camera 13 at the tip of the laser torch 19 shown in FIGS. 2 to 5, the push bolt 5 provided on the upper base plate 1 is used to perform vertical alignment and support. Gate valve 8 by bracket 2
Positioning in the left-right direction is performed according to the center.

After the position is fixed as described above, the distance from the valve seat surface 9 is set by the positioning sensor 16 at the tip of the laser torch 19 and the front-rear shaft 25, and the laser torch 19 emits He-Ne laser. Radial axis 1 is applied to the valve seat hardfacing portion 9a at the repair welding start position by the visual camera 13.
1. The position is set by the turning shaft 12.

According to the defect length, as shown in FIG. 7, all the defective portions 32 of the valve seat surface 29 are covered.
The irradiation range of the laser light is determined by the width direction range D and the circumferential direction range E in the figure, and the repair bead 30 is placed while the laser light is traveling in the traveling direction 31. The laser torch 19 oscillates in the circumferential direction and irradiates the laser light while shifting in the width direction together with the setting parameters such as the laser beam feed pitch, the scanning speed, and the output in addition to the set range. A predetermined range of the overlay can be melted. At this time, depending on the state of the defect, repair by only melting in which a laser melting portion 35 is formed as shown in FIG.
It is possible to selectively use the overlay repair in which the laser overlay 36 is formed as shown in FIG. 8B by performing while feeding the metal powder. The repairing section secures a predetermined surface accuracy by post-processing and can be reused. Here, 37 shows a cross section of the valve seat surface.

According to the present apparatus 40 as described above, it is possible to repair valves used for piping of a nuclear power plant by remote control, and as a result, it is possible to reduce the risk of exposure of workers during repair. Becomes Further, a base plate 1, a support bracket 2, and a laser torch 1 used in the present embodiment.
By preparing a number of types of guide cylinders 9 according to the dimensions of the valves, it is possible to cope with valves of various sizes.

[0027]

According to the laser repair device of the present invention, the defect generated in the valve seat caused by the laser torch mounted on the flange surface of the valve via the support arm being freely moved by the radial axis, the front-rear axis and the pivot axis. As a result of the structure that can be repaired, it is possible to repair on site the defects that occurred in the valve seat overlay of the large valve for piping, which was conventionally impossible to repair, and as a countermeasure it was replacing each valve, Furthermore, the cost of parts and the number of inspection steps are reduced. In addition, valves used in nuclear power plants can reduce radioactive waste and can perform repair work remotely,
It is also effective in reducing the risk of worker exposure.

[Brief description of the drawings]

FIG. 1 is a front view of a laser repair apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged plan view of a distal end portion of the laser repair device according to one embodiment of the present invention.

FIG. 3 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 4 is a sectional view taken along the line AA of FIG. 2;

FIG. 5 is a view taken in the direction of the arrows CC in FIG. 4;

FIG. 6 is an overall configuration diagram of a laser repair device according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram of a repair procedure by the laser repair device according to one embodiment of the present invention.

FIG. 8 is an explanatory view of a repairing method by the laser repairing device according to one embodiment of the present invention, wherein (a) shows a fusion repairing;
(B) represents the overlay repair.

[Explanation of symbols]

 Reference Signs List 1 base plate 2 support bracket 3 guide holder 4 insertion shaft 6 support arm 7 laser repair head 8 gate valve 10 rotation drive motor 11 radial axis 12 rotation axis 13 visual camera 17 optical fiber 19 laser torch 21 cable winding reel 22 guide cylinder 25 front and rear axis 26 Control device 27 YAG laser oscillator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B23K 26/08 B23K 26/08 B 31/00 31/00 D (72) Inventor Risuke Nayama 2-chome, Niihama, Araimachi, Takasago City, Hyogo Prefecture No. 1-1 Inside the Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Shoji Kushimoto 2-1-1, Araimachi Shinhama, Takasago City, Hyogo Prefecture Inside the Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Masahiko Tsumaka Takasago City, Hyogo Prefecture 2-1-1, Niihama, Arai-machi Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Haruo Shirata 2-1-1, Arai-machi, Niihama, Takasago City, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (58) Investigation field (Int. Cl. ⁶ , DB name) B23K 26/00-26/18

Claims (2)

(57) [Scope of request for utility model registration] 1. A support arm detachably attached to and fixed to a flange surface of a valve, a base end of which is rotatably held at a distal end of the support arm via a pivot shaft, and a laser beam from the distal end. A laser torch for emitting the laser torch, a radial axis interposed between the support arm and the laser torch, and capable of moving the laser torch along a radial direction of rotation around the base end side of the laser torch; A front-rear axis interposed between an arm and the laser torch and enabling the laser torch to move in the axial direction of the turning axis; and a remote control of the radial axis, the front-rear axis, and the turning axis connected to the support arm and connected to the support arm. And a controller for repairing a defect generated in the valve seat of the valve. 2. A method for selectively supplying or stopping supply of metal powder under control of a controller in combination with a laser beam emitted from a laser torch, supplying the metal powder, and repairing the buildup and removing the metal powder. 2. The laser repair apparatus according to claim 1, further comprising a powder feed nozzle capable of performing a melt repair performed by stopping the supply.