JP2989686B2 - Internal pump motor attachment / detachment method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting and dismounting an internal pump motor of an internal pump disposed below a reactor pressure vessel of a boiling water reactor and, more particularly, to a method for storing a guide screw. And improvement of the device.

[0002]

2. Description of the Related Art In a boiling water reactor equipped with an internal pump, an internal pump motor is detached from a motor casing at the time of periodic inspection or the like, and is re-attached to the motor casing after the inspection. The mounting and dismounting of the internal pump motor is performed by an internal pump motor mounting and dismounting device using a guide screw. FIG. 8 shows an internal pump motor attaching / detaching device using a guide screw of a conventional boiling water reactor. A motor casing 2 is integrally attached to a lower portion of the reactor pressure vessel 1. As shown in FIG. 9, a pair of guide screws 4 are mounted on both side surfaces of the motor casing 2 via guide screw supports 3. The guide screw support 3 includes a casing mounting plate 5 formed in the same arc shape as the outer cylindrical surface of the motor casing 2, and a lug 6 protruding from the casing mounting plate 5.
It is fixed to the motor casing 2 by mounting bolts 7. Further, the guide screw 4 is fixed to the lug 6 at the upper trunnion 9 having the lug 8 by the fixing pin 9.
A guide screw nut 11 is screwed on the lower side, and a lower end is further provided with a spline shaft for coupling with a guide screw driving device 12a of an internal pump motor elevating device 12 at the lower end. A joint 13 is attached. On the other hand, below the reactor pressure vessel 1, a swiveling platform 14 is installed as shown in FIG.
An internal pump motor elevating device 12 provided with a guide screw driving device 12a is supported in the inside thereof so as to be able to move up and down. In the lower part of the reactor pressure vessel 1, ten internal pumps are arranged along the circumferential direction.

Next, a description will be given of the work of attaching and detaching the internal pump motor 15. When sequentially handling the internal pump motor 15 of the internal pump provided in the lower part of the reactor pressure vessel 1, the internal pump motor is moved up and down directly below the motor casing 2 of the target internal pump to be handled. The turning platform 14 is turned so that the device 12 is positioned, and the internal pump motor elevating device 12 is raised to a fixed position near the upper floor surface of the turning platform 14. Then,
The internal pump motor 15 mounted on the internal pump motor elevating device 12 is fixed by guide screw nuts 11 and 11 screwed to a pair of guide screws 4 and 4 on both side surfaces thereof. , 4 are connected to the universal screw joints 13, 13 which are respectively attached to the lower ends of the guide screw driving devices 12a, 12a. Next, guide screw driving devices 12a, 12
is driven to rotate the guide screws 4 and 4 via the universal joints 13 and 13, the guide screw nut 1
1 and 11 move upward to insert the internal pump motor 15 into the motor casing 2. On the other hand, when removing the internal pump motor 15 from the motor casing 2, the operation is performed in a procedure reverse to the above operation. When handling the next internal pump motor 15, the above operation is performed for the next target internal pump.
First, the guide screws 4 and 4 are removed from the previously handled motor casing 2 while being integrated with the guide screw supports 3 and 3, respectively, and are mounted on the next target motor casing 2 to perform work. . By the way, the guide screw 4 is heavy and long,
In addition, the swivel platform, which is the main work space when working with the internal pump motor 15,
It is mounted considerably higher than the upper 14 floors. For this reason, the replacement work of the guide screw 4 requires a lot of time and manpower, and involves danger. Therefore,
In order to safely and labor-savingly replace the guide screw 4, as shown in a position A in FIG. 8, an electric chain block is provided directly above the pair of guide screws 4, 4 arranged on both sides of the motor casing 2. Temporarily set 16,16. The electric chain block 16 is an internal pump motor drop prevention support for preventing the internal pump motor 15 inserted into the motor casing 2 from dropping.
17 is temporarily provided at the lower portion of the reactor pressure vessel 1 via a fall prevention support mounting frame 18 to be mounted. The electric chain block 16 suspends the hanging ear 8 of the guide screw 4 shown in FIG. 9, removes the mounting bolt 7, and removes the guide screw 4 from the motor casing 2 while being integrated with the guide screw support 3. At this time, since the internal pump motor 15 is not handled, the internal pump motor elevating device 12 is housed at a position below the turning platform 14. Next, the internal pump motor elevating device 12 is moved upward to a position intermediate between the upper position and the lower position, and one of the electric chain blocks is moved.
The guide screw 4 is lowered by suspending the guide screw 4 by operating the guide screw 4 and the lower end of the guide screw is supported on the guide screw driving device 12a of the internal pump motor elevating device 12. Thereafter, as shown in FIGS. 8 and 10, on the floor surface of the upper frame 14a of the revolving platform 14, guides arranged on the same straight line connecting the pair of guide screws 4 and 4 on both sides of the internal pump motor elevating device 12 are provided. Screw upper clamp device 20A, one clamp 21 of 20A
Is manually advanced to the H position (forward position) shown in FIG. Here, the guide screw upper clamp device 20A
Is a pair of guide rods 24, 24 attached via a pair of brackets 23a, 23b provided on the upper surface of the turning platform 14, and a pair of U-shaped guides provided opposite the upper surface of the turning platform 14. A rail 27 is slidably guided by rails 25, 25 and guide rods 24, 24. A guide rod 25, 25 is guided via traveling wheels 26, 26 and is capable of moving forward and backward. Mounted clamps
A drive mechanism 29 including a manual handle 28 for operating the rod 21; and a turning platform 14 for moving the rod 27 forward and backward.
The lock pin 30 is configured to be fixed to The forward position of the rod 27 is a position where each clamp 21 can grip the guide screw 4. Rod 27
Is advanced, the guide screw upper clamp device 20A is fixed by the lock pin 30 and the manual handle 28 of the drive mechanism 29 connected by the clamp 21 and the rod 27 is operated, so that the clamp 21
Is pinched from both sides so as not to be completely grasped, so that the guide screw 4 can be slid vertically.
Such an operation is also performed on the other guide screw 4, and the two guide screws 4 are supported at their lower ends by the guide screw driving device 12a, and the clamps 21 of the guide screw upper clamp device 20A are provided at the intermediate portion. To a state where it is supported in a slidable guide state. Next, the internal pump motor elevating device 12 is lowered again to the original lower position, and thereafter, as shown in FIGS.
In order to avoid interference with the guide screw lower clamping device 20B attached to the lower frame 14b, the guide screw nuts 11, 11 screwed to the respective guide screws 4, 4 are removed. Here, the guide screw lower clamp device 20B is disposed at a position where the guide screw 4 vertically supported by the above-described guide screw upper clamp device 20A can be clamped, and is mounted on the lower frame 14b of the turning platform 14. It comprises a clamp support frame 31 attached thereto and a clamp 32 attached to the clamp support frame 31 so as to be able to grip the guide screw 4. After removing the guide screw nut 11 from the guide screw 4, the electric chain block 16 is operated again to lower the guide screw 4 and move the upper clamp device 20A backward,
The guide screw support 3 is manually moved to the position G shown in FIG. 10, the guide screw support 3 is seated on the bracket 23, and the weight of the guide screw 4 is completely supported by the bracket 23. Grab 21. Next, the clamp piece 32 of the clamp 32 supported by the clamp support frame 31 so as to be openable and closable by the guide screw lower clamp device 20B.
a and 32b are closed from both sides of the guide screw 4, respectively, and the clamp piece 32 of the clamp 32 is fixed with the wing bolt 32c.
By fixing a and 32b to each other, the lower part of the guide screw 4 supported by the guide screw upper clamping device 20A is fixed so as not to swing, and the guide screw 4 is stored in the turning platform 14. According to such a storage method, the pair of guide screws 4, 4 removed from the motor casing 2 can be stored in the turning platform 14 as shown in a position B in FIG.
When the internal pump motor 15 to be handled next is reattached to the motor casing 2 as shown in the position A in FIG. 8, the operation reverse to the above is performed.

[0004]

However, the above-described method for storing the guide screw 4 is such that the guide screw 4 which is originally suspended in a natural state where only gravity acts on the guide screw 4 can be taken in the lateral direction. There is still some danger because it will be temporarily suspended diagonally because it is stored in the device, and the clamp device itself has a mechanism for moving forward and backward, a mechanism for opening and closing the clamp by remote means, etc. Therefore, a large and complicated structure is required as a clamping device, and a considerably large space is required on the rotating platform floor surface on both sides of the internal pump motor elevating device 12 as an installation space for the guide screw upper clamping device 20A. To adversely affect the accessibility of the internal pump motor elevating device 12 from the side. There is a problem. Further, the handleability of the guide screw 4 alone is that the guide screw 4 must be removed from the motor casing 2 for each guide screw support 3 at the upper part, and the guide screw 4 at the lower part of the guide screw 4.
Since the guide screw nut 11 screwed into the nut must be removed each time by a human system, extra work is required. In addition, since the operation of storing the guide screw 4 is complicated, it takes a lot of time to replace the guide screw 4. The fact that it takes a lot of time to replace the heavy and long guide screw 4 is a problem particularly in the case of work in a bad environment such as below the reactor pressure vessel 1. is there.

Accordingly, an object of the present invention is to perform a work of replacing a pair of guide screws for attaching and detaching an internal pump motor by simply suspending the guide screw with a chain block without removing the guide screw nut from the guide screw. The guide screw can be easily housed in a simple operation of only the vertical movement of the guide screw alone by the chain block in the up and down direction and the rotation of the swivel platform, whereby the guide screw can be replaced. It is an object of the present invention to provide an internal pump motor attaching / detaching method and an apparatus thereof that can perform work in a short time and safely.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a support member mounted on a motor casing of each of a plurality of internal pumps disposed circumferentially below a reactor pressure vessel. A pair of guide screws, each of which has an upper end supported when the pump motor is raised and lowered and a member engaged with the internal pump is screwed in between, and a driving device detachably connected to lower ends of the pair of guide screws. And a lifting / lowering device mounted on a swivel platform disposed below the reactor pressure vessel so as to be vertically movable, and the swivel platform passes through the axes of a pair of guide screws and the center of the swivel platform.
To on concentric circles, and are disposed on different sides from each other with respect to the lifting device has an opening along the turning direction of the turning platform provided with the insertion portion of the guide screw, a pair of upper support device equipped with cushioning member And a pair of lower gripping devices that are detachably mounted on the turning platform below the upper support device, provided with a pair of clamp pieces capable of gripping the guide screw, and mounted with a buffer member. .

[0007]

The upper ends of a pair of guide screws are supported on a motor casing of a desired internal pump via a support member, and the lower ends are connected to a driving device to be driven to rotate. The pump motor is raised or lowered to a predetermined position and is attached to and detached from the motor casing. After this attachment and detachment, the turning platform is turned to a position in front of one of the guide screws. Is turned to one position of the guide screw, one of the guide screws is stored in the turning platform via one upper support device and the lower holding device, and thereafter, the turning platform is turned to the position in front of the other guide screw, Then, move the other side of the guide screw downward, and turn Ttohomu pivots the to the other position of the guide screw, housing the other guide screw to pivot the platform through the other of the upper support device and the lower gripping device.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. First, an apparatus used in one embodiment of the present invention is shown in FIG.
This will be described with reference to FIG. In the figure, 1 is a reactor pressure vessel, 2 is a motor casing disposed along the circumferential direction below the reactor pressure vessel 1, and a pair of guide screw supports is provided on both sides of the motor casing 2. 3,
3 (however, only one side is shown in FIG. 9) and FIG.
A pair of guide screws 4 and 4 are attached in the same configuration as described above. Here, the guide screw support 3 is shown in FIG.
As shown in FIG. 1, the motor casing 2 is composed of a casing mounting plate 5 formed in the same arc shape as the outer cylindrical surface, and a lug 6 protruding from the casing mounting plate 5. It is fixed to 2.
The guide screw 4 is rotatably attached to the lug 6 at a portion of the upper trunnion 9 having a suspension lug 8 by a fixing pin 10, and a guide screw nut 11 is screwed downward and further to the lower end. The universal shaft joint 13 having a spline shaft for coupling with the guide screw driving device 35a of the internal pump motor elevating device 35 is mounted. The internal pump motor elevating device 35 and the guide screw driving device 35a
Is a conventional internal pump motor elevating device described above.
Although the configuration is slightly different from that of the guide screw driving device 12 and the guide screw driving device 12a, the function is the same.

The electric chain blocks 16, 16 are mounted on the motor casing 2 directly above the guide screws 4, 4 via a chain block support 36. The chain block support 36 has a band shape and is always fixed to the outer periphery of the motor casing 2. Therefore, a swing mechanism is provided so as not to interfere when the internal pump motor fall prevention support 17 is used, and the structure is such that the electric chain block 16 can be easily attached and detached.
It should be noted that the chain block support 36 is composed of ten internal pumps 37, which are individually disposed below the reactor pressure vessel 1.
Is mounted on the motor casing 2 each time. On the other hand, the electric chain block 16 can be easily and manually attached to the chain block support 36 by utilizing the upper working space (formed between the reactor containment vessel and the reactor pressure vessel) 38. .

Further, as shown in FIG. 2, the turning platform 14 has a plane position on the same circumference as the pair of guide screws 4 and 4 and a left and right centered on the internal pump motor elevating device 35. The guide screw upper support device 39A is provided at the symmetric positions X and Y along the vertical direction, respectively.
And the guide screw lower clamp device 39B are mounted. Here, the guide screw upper support device 39A is attached to the upper frame 14a of the turning platform 14,
Guide screw lower clamp device 39B is lower frame
Attached to 14b.

As shown in FIGS. 3 and 4, the guide screw upper support device 39A is attached to the upper frame 14a by a fixing plate 40a.
And a step portion 42 provided on the upper surface of the clamp device frame 41 for regulating a positional displacement in the horizontal direction in a seated state of the guide screw 4 along a circumferential direction. , This step
The guide screw 4 has a slit 43 having a semicircular portion 43a and an opening 43b for accommodating and seating the guide screw 4 so as not to damage the guide screw 4, and is constituted by a seat plate 44 made of nylon material. Here, the clamp device frame 41 and the opening 43b of the slit 43 are arranged along the tangential direction of the circumference with respect to the turning center of the turning platform 14. Note that reference numeral 45 in FIG. 3 indicates a housing portion. As shown in FIGS. 5 to 7 , the guide screw lower clamp device 39B includes a clamp device mount 47 attached to the lower frame 14b via a support member 46, and support shafts 48, 48 mounted on the clamp device mount 47. And a pair of clamp pieces 51a and 51b attached to the clamp support frame 49 so as to be openable and closable via a hinge 50, and the pair of clamps. Pads 52a, 52b formed of nylon material for clamping the screw portion of the guide screw 4 so as not to damage the pieces 51a, 51b, and guide grooves 49a, 49b provided in an arc shape in the clamp support frame 49. The fixing pins 53a, 53b for guiding and fixing the clamp pieces 51a, 51b in an open state and the clamp pieces 51a, 51b in a closed state (the guide screw 4). It is composed of a wing bolt 54 for fixing to each other in the supporting state).

Next, the operation of the embodiment configured as described above will be described. In order to handle the internal pump motor 15 sequentially by using the internal pump motor elevating device 35 and the guide screw 4, when replacing the guide screw 4, first, the motor casing shown at the position A in FIG. The guide screw 4 attached to the guide screw 2 is suspended by the electric chain block 16 via the suspension ear 8 (shown in FIG. 9). Next, guide screw support 3
The fixing pin 10 (shown in FIG. 9) is attached to the motor casing 2 and the upper trunnion 9 of the guide screw 4 is attached.
9 (shown in FIG. 9), and the connection with the lug 6 (shown in FIG. 9) is released. Thereby, the guide screw 4
Will be hung on the electric chain block 16 in a balanced and natural state.

Next, with respect to the guide screw upper support device 39A installed in the turning platform 14,
The turning platform 14 is turned until the guide screw 4 is at a position where the guide screw upper support device 39A shown in the position D in FIG. 4 does not interfere with the guide screw nut 11 screwed to the lower portion of the guide screw 4. . Thereafter, the electric chain block 16 is actuated to lower the guide screw 4 to a position where the guide screw nut 11 does not interfere with the guide screw upper support device 39A and does not interfere with it, and then temporarily stops.

Next, the turning platform 14 is further turned slightly at a lower speed, and the guide screw 4 is inserted into the center of the slit 43 of the seat plate 44 of the guide screw upper support device 39A, that is, the position shown at the position C in FIG. And the turning platform 14 is stopped. Thereafter, the electric chain block 16 is operated again, and the guide screw 4 is further lowered, and the housing 45 of the upper trunnion 9 (shown in FIG. 9) of the guide screw 4 is placed on the seat plate 44 of the guide screw upper support device 39A. To sit on.

Next, as shown in the F position of FIGS. 5 and 6, the guide screw lower clamp device 39B, which is mounted so as not to interfere with the guide screw nut 11 when the guide screw 4 descends, is supported. axis
The support shaft 48 is once lifted and removed from the clamp device mounting table 47 so that the 48 is disengaged from the clamp device mounting table 47, and then inverted, and then the support shaft 48 is inserted into the clamp device mounting table 47 again, as shown in a position E in FIGS. Attach to After this, FIG.
In the state where the clamp pieces 51a and 51b are open, the fixing pins 53a and 53b are picked up to release the fixation, and the clamp pieces 51a and 51b are moved along the guide grooves 49a and 49b. Close the guide screws 51b so as to sandwich the guide screws 4 from both sides. Thereafter, with the pads 52a, 52b attached to the clamp pieces 51a, 51b being in close contact with the guide screw 4, the clamp pieces 51a, 51b are manually connected to the wing bolts 54.
Fix with. As a result, the guide screw 4 is securely stored in the turning platform 14. Thereafter, the electric chain block 16 is removed from the guide screw 4.

Further, the same operation as described above is performed on the other guide screw 4, whereby the pair of guide screws 4, 4 are securely inserted into the turning platform 14 as shown in the position B in FIG. Is stored. When the other internal pump motor 15 is handled, the above operation is performed in the reverse order, so that the motor casing 2 corresponding to the target internal pump is provided.
The pair of guide screws 4 can be replaced.

[0017]

As described above, according to the present invention, the internal pump motor can be moved up and down by a pair of guide screws so that it can be attached to and detached from the motor casing. Center of swivel platform
The guide screw upper support device and the guide screw lower clamp device are mounted vertically on the same circumference around the center and symmetrically around the internal pump motor elevating device. Through the use of the electric chain block, the guide screw can be easily stored in the swivel platform by only the lifting and lowering operation of the guide screw itself suspended in a natural state and the swivel operation of the swivel platform.
This makes it easy to replace guide screws,
It is safe and can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of the present invention by partially cutting it.

FIG. 2 is an explanatory diagram showing an arrangement position of a main part according to one embodiment of the present invention.

FIG. 3 is a front view showing a guide screw upper support device according to one embodiment of the present invention.

FIG. 4 is a plan view taken along the line LL of FIG. 3;

FIG. 5 is a side view of a guide screw lower clamping device according to an embodiment of the present invention.

FIG. 6 is a plan view taken along the line MM in FIG. 5;

FIG. 7 is a configuration diagram of a guide screw lower clamping device shown in FIG. 6;

FIG. 8 is a perspective view showing a partially cutaway configuration of a guide screw and a turning platform for handling a conventional internal pump motor.

FIG. 9 is a perspective view showing a configuration of a conventional guide screw alone.

FIG. 10 is a plan view of a conventional guide screw driving device.

FIG. 11 is a conventional guide screw lower clamping device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Motor casing, 3 ... Guide screw support, 4 ... Guide screw, 11 ... Guide screw nut, 14 ... Revolving platform, 14a
... Upper frame, 14b ... Lower frame, 15 ... Internal pump motor, 16 ... Electric chain block, 35 ... Internal pump motor elevating device, 35a ... Guide screw drive device, 39A ... Guide screw upper support device, 39B
... Guide screw lower gripping device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G21C 19/02 G21C 15/243

Claims (2)

(57) [Claims] An upper end of a pair of guide screws is supported by a desired motor casing of a plurality of internal pumps disposed along a circumferential direction below a reactor pressure vessel via a support member, and a lower end of the guide screw is connected to a lower end of the reactor pressure vessel. The internal pump motor is moved up or down from a predetermined position to a predetermined position via a member screwed in the middle, and is attached to and detached from the motor casing. The swivel platform disposed below the reactor pressure vessel is swirled to one of the front positions, and then one of the guide screws is moved downward, and the swivel platform is again moved to one position of the guide screw. Pivoted through one upper support device and one lower grip device mounted on the pivot platform along the vertical direction. Then, one of the guide screws is housed in the turning platform, and thereafter, the turning platform is turned to a position in front of the other of the guide screws, the other of the guide screws is moved downward, and the turning platform is again moved to the guide. The screw is turned to the other position, and the other of the guide screws is housed in the turning platform via the other upper support device and the lower holding device mounted on the turning platform along the vertical direction. How to attach and detach the internal pump motor. 2. A support member mounted on each motor casing of a plurality of internal pumps disposed along a circumferential direction at a lower portion of a reactor pressure vessel. A pair of guide screws in which a member engaged with the internal pump is screwed in the middle, and a driving device detachably connected to lower ends of the pair of guide screws. A lifting device movably mounted on a swiveling platform disposed below the pressure vessel,
The pair of guide screws are mounted on the turning platform.
Around the center of rotation of the platform
On the concentric circles, and disposed at symmetrical positions on different sides with respect to the elevating device, provided with an insertion portion of the guide screw, and having an opening along the turning direction of the turning platform, the buffer member A pair of mounted upper supporting devices, and a pair of openable and closable clamp pieces which are detachably mounted on the turning platform below the upper supporting devices and are capable of gripping the guide screw,
An internal pump motor attachment / detachment device comprising a pair of lower holding devices equipped with a buffer member.