JP2735398B2 - Peripheral surface processing equipment in cylindrical narrow space - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle portion provided in a lower mirror of a reactor pressure vessel of, for example, a boiling water reactor (BWR), and a motor casing of a recirculation pump in the reactor inserted into the nozzle portion. The present invention relates to a peripheral surface machining apparatus in a cylindrical narrow space, which is applied when, for example, a back bead of a weld bead formed in a narrow air gap on the outer periphery of a motor casing by butt welding is ground in the air gap. .

[0003]

2. Description of the Related Art For example, an improved boiling water reactor (A-BW)
R) is provided with an in-reactor recirculation pump (RIP) for circulating a coolant in a reactor pressure vessel (RPV).
The motor casing of the in-reactor recirculation pump is abutted from below into a nozzle portion provided in the lower mirror of the reactor pressure vessel and joined by butt welding. This welding is performed from the inner peripheral side of the nozzle and the motor casing.

Since the nozzle of the lower mirror of the reactor pressure vessel is thermally deformed three-dimensionally due to thermal expansion or the like during operation, a joint between the nozzle and the motor casing is formed for the purpose of preventing stress generation. Air gap around, width 2
A cylindrical narrow space of about 5 mm is formed. The inner peripheral side of the butt weld is finished by boring or the like, but the outer rim of the nozzle, that is, the back side of the weld bead that rises convexly at a height of about 2 mm on the air gap side, Since the air gap is narrow, it has not been particularly finished so far.

[0005]

In the inspection during or after welding, if a defect is found in the above-mentioned undercut portion, the portion is finished smoothly, and it is confirmed whether or not it is an actual welding defect. It is desirable to do. That is, in the case of performing an ultrasonic flaw detection test on a butt welded portion between cylindrical parts, it is desirable that the flaw detection site is a flat surface on both the inner and outer surfaces due to the restriction of the flaw detection principle.

[0006] In this case, in order to smooth out the backwash of the weld bead between the nozzle and the motor casing in the above-mentioned reactor pressure vessel, a processing device is inserted into a narrow air gap, and the welding line is internally formed. A mechanism such as turning along or sliding up and down is required.

However, as described above, the air gap is 25
It is a narrow cylindrical space with a width of about mm, and a skirt of approximately the same diameter hangs down from the lower mirror's nozzle at the part that rises in a spherical shape below the nozzle to support the motor casing. It has a long shape. For this reason, it is not possible to easily remove the protruding portion of the backwash with a normal grinding device or the like.

[0008] The same problem can occur in other than the nuclear reactor. In other words, when a double tubular structure is welded from the inner peripheral side, or when drilling or other processing is performed, the back bead or burrs of the weld bead is relatively small in the gap between the two tubes, and In some cases, irregular convex shapes may occur, and even in this case, it is desirable to accurately remove flats, flashes, and the like into a flat shape, but that portion may be difficult to machine with a normal device. .

The present invention has been made in view of such circumstances, and has been made in consideration of processing of a peripheral surface arranged in a narrow cylindrical space,
In particular, it is an object of the present invention to provide a peripheral surface processing apparatus in a cylindrical narrow space that can easily and surely perform a finishing process on a back bead of a weld bead. [Configuration of the invention]

[0010]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an arc-shaped plate divided in the circumferential direction with a size that can be inserted into a narrow cylindrical space in which a peripheral surface to be processed is arranged. A plurality of ring-shaped units composed of a plurality of ring-shaped elements, and each ring-shaped unit can be detachably attached to each unit along the axial direction and each element along the circumferential direction within a range substantially flush with the inner and outer peripheral surfaces thereof, and And joining means for integrally moving in the axial direction and the circumferential direction as one unit, and the one ring-shaped unit disposed at one end in the axial direction is used as a processing unit, and the processing unit is provided with processing means that can be remotely operated. Along with the other ring-shaped unit disposed at the other end in the axial direction as a drive unit, an axial moving means for causing the drive unit to move in the axial direction and a circumferential movement are performed. Characterized in that a circumferential moving means causes I.

[0011]

According to the present invention, the peripheral surface can be machined if an opening into which each element can be inserted is present in the cylindrical narrow space.

That is, the arcuate plate-like element is inserted into the space from the opening and connected in the circumferential direction by the joining means to assemble the ring-shaped unit in the space. When the assembly of one ring-shaped unit is completed, it is moved in the axial direction, and another ring-shaped unit is assembled in the same manner as described above, and this is sequentially connected to the previously assembled unit by joining means.

The assembling or installation of the processing means, the axial moving means, the circumferential moving means and the like is performed together with the above-mentioned unit assembly or before and after the unit assembly.

[0014] When the insertion of the working unit, the drive unit, etc. into the space and the assembling or installation of the working means, the axial moving means, the circumferential moving means, etc. are completed by such an operation, the axial moving means, While the whole unit is moved in the axial direction and the circumferential direction by the circumferential direction moving means, the processing means is remotely operated to perform the peripheral surface processing in the space.

After the machining, the components are disassembled and removed from the space by the reverse operation of the assembling procedure.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In this embodiment, the nozzle provided on the lower mirror of the reactor pressure vessel of the boiling water reactor and the motor casing of the in-reactor recirculation pump inserted into the nozzle are butt welded. The present invention is applied to a case where a back side of a welding beam formed in a narrow air gap on the outer periphery of a motor casing is ground in the air gap. FIG. 2 shows a lower cross-sectional structure of the reactor pressure vessel, and FIG. 3 shows a motor casing joint structure of the recirculation pump in the reactor.

FIG. 2 shows, for example, 1300 MW
This is a reactor pressure vessel for an advanced boiling water reactor. As shown in the figure, a nozzle 2 provided in a lower mirror 1a of the reactor pressure vessel 1 and a motor casing 4 of a recirculation pump 3 in the reactor inserted into the nozzle 2 are butt-welded.

This butt welding is performed from the inside of the nozzle 2 and the motor casing 4. As shown in FIG. 3, in the welded portion 5, an air gap, which is a narrow cylindrical space around the nozzle 2 and the motor casing 4, is provided. At 6, a backwash 7 of the welding beam protrudes. A skirt 8 protrudes from the lower mirror 1a of the reactor pressure vessel 1 below the nozzle 2, and a projection 9 on the outer peripheral portion of the motor casing 4 is applied to an inner peripheral surface of a lower portion of the skirt 8. In contact. An opening 10 having a constant area is formed in a lower portion of the skirt 8.

FIGS. 1 and 4 show the assembled state of the processing apparatus A according to the present embodiment, and FIGS. 5 to 8 show the parts configuration of the processing apparatus A in an exploded state.

The processing apparatus A is roughly divided into a processing unit 11 and a drive unit 1 which are arranged at upper and lower positions.
2, two connecting units 13 and 14 for connecting these vertically, a processing means 15 provided in the processing unit 11, an axial moving means 16 for causing the drive unit 12 to move in the axial direction, and a circumferential movement. And a support unit 18 for supporting them.

The processing unit 11 includes thin circular plate-like elements 11a, 11b, 11c, 1 divided into four in the circumferential direction.
1d, and these are assembled into a ring shape as a whole. As for each of the elements 11a to 11d, adjacent elements are mutually connected with two kinds of circumferential joining means 19, 20.
Thereby, it is joined so that it can move integrally in the circumferential direction and is detachable.

The first circumferential joining means 19 joins a pair of adjacent elements 11a and 11b so as to be relatively movable in the circumferential direction.
1 and a cylinder mechanism 22 for mutual separation. Fluid pressure is supplied to the cylinder mechanism 22 from a compressed fluid supply source (not shown) via a hose 23, and fluid pressure control is similarly performed by a control signal of a remote operation means (not shown).

The second circumferential joining means 20 is for connecting the joining parts of the elements 11a to 11d other than the above-mentioned joining parts in a fixed state. As shown in FIG. It comprises a fixture 25 such as a screw for fixing this to the outer peripheral surfaces of the elements 11a to 11d.

Each of the circumferential joining means 19 and 20 is assembled so as to be housed in a groove formed in each of the elements 11a to 11d, and is located within a range substantially flush with the inner and outer peripheral surfaces of each of the elements 11a to 11d. Can be stored.

One element 11a is provided with a processing means 15
Is provided. The processing means 15 includes a processing tool 26 such as a rotary grinding tool protruding above the element 11a,
An air tool 27 for applying a rotational force to the processing tool 26 is provided. As the processing tool 26, for example, a rotary bar, a grindstone, a flapping wheel, or the like is applied. Fluid pressure is supplied to the air tool 27 from a compressed fluid supply source (not shown) via a hose 28, and fluid pressure control is similarly performed by a control signal of a remote operation means (not shown).

In addition, a T-shaped slot 29 for forming a radial joining means is formed at the lower edge of each of the elements 11a to 11d.
Are formed respectively.

The connecting units 13 and 14 are thin arc-shaped plate-like elements 13a to 13 divided into four in the circumferential direction, respectively.
d, 14a to 14d, and these are assembled into a ring shape as a whole. Each of these elements 13
The shapes and joining structures of a to 13d and 14a to 14d are as follows:
Since the elements are substantially the same as the elements 11a to 11d of the processing unit 11, the description of the parts is omitted, and the corresponding parts are denoted by the same reference numerals. However, as shown in FIG. 6, each of the elements 13a to 13d, 14a to 14d
The point that a T-shaped hook 30 forming a radial joining means is formed at the upper end edge of
It is different from the case. The hook 30 is fitted into the T-shaped slot 29 of another element located above to form the axial joining means 31. That is, it is used for joining with the processing unit 11 and joining between the connecting units 13 and 14.

The height of the entire processing apparatus can be adjusted by combining the connecting units 13 and 14 in a plurality of stages or by changing the height.
Note that three or more sets can be provided as necessary.

The drive unit 12 is provided with four thin circular arc-shaped plate elements 12a to 12d which are divided into four parts in the circumferential direction. Each element 12a to 12d of the drive unit 12
While each of the lower end outer peripheral surfaces has a portion to be the gearing portion 32, the lower end edge is a flat surface having no T-shaped slot. Other points are the above-mentioned units 11, 1
Since they are substantially the same as 3 and 14, corresponding parts are denoted by the same reference numerals as above and description thereof is omitted.

The support unit 18 is provided with each of the above units 1
1, 2, 13, and 14 are rotatably supported, and are circularly arcuate plate-like elements 18 a to 18 divided into four in the circumferential direction.
A flat base plate 33 on which the circumferential moving means 17 is mounted is connected to one element 18a. The circumferential joining of the elements 18a to 18d is substantially the same as that of the elements 11a to 11d and the like.

As shown in FIG. 4, a flange-shaped engaging portion 34 is provided on the upper portion of the support unit 18 with a large diameter at the tip, and this engaging portion 34 is formed at a lower portion of the drive unit 12. The drive unit 12 is inserted into the inward ring-shaped engagement groove 35, whereby the drive unit 12 is supported by the support unit 18 so as to be slidable in the circumferential direction and movable integrally in the axial direction.

The support unit 18 has a bracket 36 for supporting the base plate 33. Bracket 3
6 is fixed below the opening 10 of the skirt 8 via a fixture 36a such as a screw, and supports the base plate 33 via the axial moving means 16 so as to be able to move in the axial direction, that is, to move up and down. It has become.

The axial moving means 16 has a driving motor 37 detachably supported by a bracket 36 and a screw jack 38 driven by the motor 37. Is screwed into the bracket 36, and the base plate 33 of the support unit 18 is connected to the upper end of the screw 39 so as to be able to move up and down. The motor 37 may be omitted, and the screw jack 38 may be driven manually.

The circumferential moving means 17 includes a drive motor 40 detachably supported on a base plate 33 and a gear device 41 for transmitting the rotation of the motor 40 to the gearing portion 32 of the drive unit 12. And This gear device 4
1 through a gearing part 32 driven to rotate by
The drive unit 12 moves in the circumferential direction on the support unit 18,
That is, they are driven to rotate, thereby connecting units 14, 1
The processing unit 11 and, consequently, the processing means 15 are pivotally driven through the rotation of the processing unit 3 sequentially.

The above units 11, 12, 1
A predetermined portion of the elements constituting the elements 3, 14 and the like, for example, the element 11a provided with the processing means 15 and the elements 12a, 13a, 14a and the like below the elements 11a, A pair of through holes 42 penetrating in the direction is provided. Although not shown, a small borescope or a CCD camera or the like is inserted into these through holes 42 so that the state of the processed portion can be observed or accurate positioning can be performed. Similarly, although not shown, a tube or the like of a vacuum pump is inserted so that chips generated by processing can be collected.

Next, an assembling procedure will be described.

(1) First, the three elements 18b, 18c and 18d of the support unit 18 are sequentially inserted into the air gap 6 from the opening 10 of the skirt 8, and these are inserted into the air gap 6 by the circumferential connection means 20. After connecting,
The element 18a having the base plate 33 is connected. Thus, the support unit 18 is assembled in a ring shape within the air gap 6 with the base plate 33 exposed from the opening 10 of the skirt 8.

(2) Next, the bracket 36 is attached to the skirt 8 together with the axial moving means 16, and the screws 39 of the axial moving means 16 support the base plate 33 from below. The base plate 33 is located at the lowermost end of the opening 10.

(3) Then, the respective elements 11a to 11d of the processing unit 11 are sequentially inserted into the air gap 6 from the opening 10 of the skirt 8 in the same manner as described above, and these are connected to the connecting piece 24 and the fixture in the air gap 6. 25 are connected by the circumferential connection means 20. The element 11a having the processing means 15 is finally assembled, and at this time, the element 11a is joined to the adjacent element 11b by a circumferential connection means 19 comprising a spring 21 and a cylinder mechanism 22.

(4) Thereafter, the processing unit 11 is lifted, and in this state, the respective elements 13a to 13d of the upper connecting unit 13 are inserted from the opening 10 of the skirt 8,
T-shaped hooks 30 as axial connection means 31 protruding from the upper ends thereof are inserted into the slots 29 at the lower ends of the elements 11a to 11d of the processing unit 11 to perform the axial connection, and the connection unit 13 The circumferential connection of the elements 13a to 13d is performed.

(5) Then, as described above, the processing unit 1
1 and the upper connecting unit 13 are lifted, and in this state, the lower connecting unit 14 is opened through the opening 10 of the skirt 8.
, And the T-shaped hook 30 at the upper end is inserted into the groove 29 at the lower end of the element 13a to 13d of the upper connection unit 13 to perform axial connection, and the connection unit 14 The circumferential connection of the elements 14a to 14d is performed.

(6) The processing unit 11 and the upper and lower connection units 13, 1 connected in the axial direction to each other
4, the elements 12a to 12d of the drive unit 12 are sequentially inserted from the opening 10 of the skirt 8 in this state. Then, the T-shaped hook 30 of each of the elements 12a to 12d is connected to the element 1 of the lower connecting unit 14.
4a to 14d, the flanges 34 of the support unit 18 are inserted into and engaged with the ring-shaped engagement grooves 35, and then the elements 18a to 18d are circumferentially connected to each other. Then, the gearing portion 32 is assembled. As described above, the processing unit 11 at the upper end and the support unit 18 at the lower end are assembled so as to be integrally movable in the circumferential direction and the axial direction.

(7) Finally, the support unit 18
The circumferential drive mechanism 17 is mounted on the base plate 33, and the gear device 41 is engaged with the gear ring portion 32 so that the rotational force can be transmitted to the drive unit 12.

Next, a working method will be described.

By the above operations, the processing unit 11, the connecting units 13, 14, the drive unit 12, etc. are inserted into the air gap 6, and the processing means 15, the axial moving means 1
6. When the assembly of the circumferential direction moving means 17 and the like is completed, the axial position is set by the axial direction moving means 16.

When the circumferential moving means 17 is driven in this state, the drive unit 12 slides on the upper surface of the support unit 18 and the connecting units 14 and 13 and the processing unit 11
Turns together.

Then, the processing means 15 is driven to perform the peripheral surface processing in the air gap 6, that is, the grinding processing of the reverse bead 7 of the weld bead of the butt welding portion 5 between the nozzle 2 and the motor casing 4.

If necessary, the processing tool 2 of the processing means 15
6 so that the cylinder mechanism 2 contacts the backside wave 7 properly.
2, the radial dimension of the processing unit 11 based on the tensile force of the coil spring 21 is set.

Thus, the nozzle 2 and the motor casing 4
In the butt-welded portion 5, the reverse lip 7 protruding about 2 mm toward the air gap 6 is ground and finished smoothly.

Incidentally, the inner welding margin is separately removed by machining after welding.

After the processing in the air gap 6 is completed, the respective components are disassembled and removed from the space by performing an operation reverse to the above-described assembling procedure.

According to the above embodiment, the reactor pressure vessel 1
The nozzle 2 and the motor casing 4 are inserted into a narrow cylindrical air gap 6 formed at the nozzle 2 of the lower mirror 1a.
Can be processed smoothly, and the inspection and test for confirming the soundness of the welded portion can be made easier or easier.

In the above embodiment, the processing unit 11
As a circumferential joining means 19 for joining the elements 11a and 11b so as to be relatively movable in a circumferential direction, a coil spring 21 for attracting each other, and a cylinder mechanism 22 for separating each other.
However, the circumferential joining means 19 may be omitted.

For example, as shown in FIG.
The one circumferential connection means 20 may be of a fixed type, that is, may be constituted by a thin plate-shaped connection piece 24 and a fixing tool 25 such as a screw. In such a configuration, although the radial adjustment movement of the processing tool 15 is not performed, it is possible to finish the reverse bead 7 of the weld bead to a constant outer diameter, and the same operation as described above can be performed with a relatively simple configuration. The effect is obtained. In FIG. 9, other configurations are substantially the same as those of the above-described embodiment. Therefore, the same reference numerals as those in FIG.

Further, a T-shaped hook 30 and a T-shaped slot 29 are provided.
In the present invention, various modifications, for example, spring-type stoppers, are also applied to the axial connection means 31 formed by the fitting configuration of the shaft and the circumferential connection means 20 formed by the thin plate-shaped connection piece 24 and the fixing tool 25 such as a screw. It is needless to say that deformation such as application of gold is possible.

Further, in the above embodiment, each unit 11.
Are composed of four divided elements 11a, respectively.
The invention is not limited to this, and the number of divisions of the element can be set arbitrarily as long as it can be inserted from the opening 10 of the skirt 8.

Further, in the above embodiment, the object to be processed is
The butt welding portion 5 between the nozzle 2 provided in the reactor pressure vessel 1 of the boiling water reactor and the motor casing 4 of the in-reactor recirculation pump 3 is a part of the backwash 7 into the air gap 6. The present invention is not limited to this, and can be carried out by processing peripheral surfaces in various narrow cylindrical spaces.

[0059]

As described above, according to the present invention, smoothing of a back-side wave protruding into an air gap when a nozzle of a reactor pressure vessel of a boiling water reactor and a motor casing are butt-welded. For example, it is possible to easily and reliably perform processing of a peripheral surface disposed in various narrow cylindrical spaces.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIG. 2 is a sectional view showing a reactor pressure vessel of the boiling water reactor applied in the embodiment.

FIG. 3 is an enlarged view showing a main part of FIG. 2;

FIG. 4 is a sectional view showing an assembled state of the embodiment.

FIG. 5 is an exploded perspective view showing a component configuration of the embodiment.

FIG. 6 is an enlarged perspective view showing components of the embodiment.

FIG. 7 is an enlarged perspective view showing components of the embodiment.

FIG. 8 is an enlarged perspective view showing components of the embodiment.

FIG. 9 is a perspective view showing another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 6 Air gap (cylindrical narrow space) 7 Weak bead back side (peripheral surface for processing) 11 Processing unit 11a to 11d Element 12 Drive unit 12a to 12d Element 15 Processing means 16 Axial moving means 17 Circumferential moving means 19 , 20 circumferential joining means 31 axial joining means

Claims (1)

(57) [Claims] 1. A plurality of ring-shaped units each having an arc-shaped plate-shaped element divided in a circumferential direction and having a size insertable into a cylindrical narrow space in which a peripheral surface to be processed is arranged, and each of the ring-shaped units. Joining means for detachably joining each of the units along the axial direction and each of the elements along the circumferential direction within a range substantially flush with the inner and outer peripheral surfaces thereof, and as a whole integrally movable in the axial and circumferential directions. The one ring-shaped unit disposed at one end in the axial direction is a processing unit, and the processing unit that can be remotely operated is provided in this processing unit, and another ring-shaped unit disposed at the other end in the axial direction. Characterized in that an axial moving means for causing the driving unit to move in the axial direction and a circumferential moving means for causing the driving unit to move in the circumferential direction are provided. Peripheral surface processing equipment in a bottled space.