JP2899405B2 - Channel fastener handling device - Google Patents

Description

Description: Object of the Invention (Industrial Application Field) The present invention relates to a channel fastener handling device, and in particular, a channel fastener capable of preventing overtightening of a bolt of the channel fastener and dropping of the channel fastener. Related to handling equipment.

(Prior Art) A fuel assembly of a boiling water reactor is composed of a fuel handle in which a plurality of fuel rods are bundled, a channel box mounted on the outside thereof, and a channel fastener for fixing them. In general, several hundred fuel assemblies are loaded and operated in a nuclear reactor, and during periodic inspections of the nuclear reactor, about one-fourth of the fuel assemblies are It is removed from the furnace and replaced with a new fuel assembly.

After the fuel assemblies removed from the reactor during the periodic inspection are stored in the spent fuel storage pool for a certain period of time, the bolts of the channel fasteners are loosened with the channel fastener handling device, the channel fasteners are removed, and the channel box is removed. After that, it is transported to the fuel reprocessing facility with the fuel handle alone. The new fuel handle is fitted with a channel box, fixed with a channel fastener, transported to the spent fuel storage pool, and loaded into the reactor. Here, a new fuel handle may be used in combination with a channel box that has been used once. This operation is performed in the spent fuel storage pool. After attaching the old channel box to the new fuel handle, the bolts of the channel fastener are tightened using the channel fastener handling device to secure the fuel handle and the channel box.

FIG. 3 and FIG. 4 show a channel fastener 3 for fixing the fuel handle 1 and the channel box 2. The channel fastener 3 is mounted on a corner c of the channel box 2 and has a ring groove 5. The fuel handle 1 and the channel box 2 are fixed by screwing the bolt 4 to the fuel handle 1.

FIG. 5 shows a conventional channel fastener handling device for handling such a channel fastener 3. The handling device 11 includes a housing 12 having a channel guide 13 at a lower end thereof. Using the corner c of the channel box 2 as a guide, the center of the handling device 11 is aligned with the mounting center of the bolt 4 of the channel fastener 3.

In the housing 12, a wrench shaft 14 is inserted, and between the wrench shaft 14 and the housing 12, an annular stopper 15 is arranged and fixed to the housing 12, and the lower end of the wrench shaft 14 A plurality of springs 16 are formed concentrically with the wrench shaft 14 so as to be easily gripped by the bolts 4 according to the shape of the bolts 4.

One end of each of these springs 16 is fixed to an adapter 17 integral with the wrench shaft 14, and a rivet 18 is provided at the other end.

At the lower end of the wrench shaft 14, a wrench socket 19 for fitting the head of the bolt 4 to rotate the bolt 4 is provided integrally and concentrically with the wrench shaft 14.

On the other hand, the upper end of the wrench shaft 14 is screwed into a nut 20 integral with the housing 12, and the tip thereof is connected to a handle 21 for rotating the wrench shaft 14 and a torque wrench (not shown). Drive socket for 22
Are provided respectively.

In the above configuration, when attaching the channel fastener 3, first insert the head of the bolt 4 of the channel fastener 3 into the wrench socket 19, and rotate the handle 21 counterclockwise. Then, the wrench shaft 14 moves in the axial direction, the rivet 18 interferes with the stopper 15, and the spring 15
The ring 16 of the bolt 4 is gripped by the spring 16.

Thereafter, the handling device 11 is made vertical, the channel guide 13 is applied to the corner c of the channel box 2 mounted on the fuel handle 1, and the center of the bolt 4 of the channel fastener 3 is positioned at the mounting center.

Next, the handle 21 is rotated clockwise, and the bolt 4
Is loosened, a torque wrench (not shown) is connected to the drive socket 22, and the screw is rotated clockwise again to finally tighten the bolt 4 with the specified tightening torque.

On the other hand, when removing the channel fastener 3, the handle 21 is first rotated clockwise to open the spring 5, and the handling device 11 is mounted on the channel fastener 3 in this state. Then, the head of the bolt 4 is fitted into the wrench socket 19.

Next, the handle 21 is rotated counterclockwise to loosen the bolt 4. As a result, the wrench shaft 14 moves in the axial direction, the rivet 18 interferes with the stopper 15, and the head of the bolt 4 is gripped by the spring 16. If the handling device 11 is removed in this state, the channel fastener 3 is also removed.

(Problem to be Solved by the Invention) In the conventional channel fastener handling device,
At the time of the initial tightening operation by manual tightening, the tightening torque acting on the bolt 4 of the channel fastener 3 depends on the feeling of the operator, and therefore the bolt 4 may be excessively tightened more than the specified torque and damage the bolt 4. .

Further, there is no means for checking whether the wrench socket 19 is completely fitted to the bolt 4, and the tightening operation and the releasing operation of the bolt 4 are simultaneously performed by rotating the wrench shaft 19, and , The bolt 4 is loosened and grasped simultaneously by the rotation of the wrench shaft 19, so that the bolt 4 is incompletely grasped during operation, and the channel fastener 3 is moved into the spent fuel storage pool. The handling operation requires a high degree of skill.

The present invention has been made in consideration of such points,
It is an object of the present invention to provide a channel fastener handling device which can securely tighten bolts of a channel fastener without excessively tightening and which does not cause the channel fastener to drop into a spent fuel storage pool.

[Means for Solving the Problems] The present invention provides a channel fastener handling apparatus for handling a channel fastener for fixing a channel box to a fuel handle, as a means for achieving the above object. A housing having a channel guide for aligning the center of the bolt with its mounting center; a wrench socket mounted on the head of the bolt; gripping means for gripping the bolt with the wrench socket mounted on the bolt; and transmitting torque. A wrench shaft having a torque limiting means for limiting the rotation and a rotating handle, the wrench shaft being installed in the housing; a wrench shaft slidably inserted into the wrench shaft, and a lower end protruding into the wrench socket; A seating detecting means which is immersed by being attached to the part; Characterized in that was acceptable to provide each; the operation of the serial gripping means, and locking means for locking in a state of gripping the bolt.

(Operation) In the channel fastener handling device according to the present invention,
When the head of the bolt fits into the wrench socket, the seating detection means whose lower end protrudes into the wrench socket is immersed in the wrench shaft, and this slide causes the wrench socket to be mounted on the head of the bolt. It is confirmed.

Further, since the operation of the gripping means for gripping the bolt in this mounted state is locked while the bolt is gripped by the locking means, there is no possibility of dropping the channel fastener.

Also, since the wrench shaft has torque limiting means, if excessive tightening torque acts on the rotating handle,
The torque acting on the bolt is limited by the torque limiting means.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. 1 and FIG.

FIG. 1 shows an example of a channel fastener handling device according to the present invention. The handling device 31 includes a housing having a handle 33 at an upper end.
The lower end of the housing 32 is guided by the corner c of the channel box 2 shown in FIGS.
A channel guide 34 is provided which positions the center of the bolt at the mounting center of the bolt 4 of the channel fastener 3.

A wrench shaft 35 is provided inside the housing 32, and the wrench shaft 35 is supported concentrically and rotatably on the housing 32 via bearings 36, 37, and 38.

At the lower end of the wrench shaft 35, a wrench socket 39 having a socket shape corresponding to the shape of the head of the bolt 4 is provided.
Is provided integrally with this wrench socket
A gripping means 40 for gripping the bolt 4 in a state where the head is fitted to 39 is provided.

The gripping means 40 includes a cylindrical guide 41 integrated with the wrench shaft 35, and a portion of the cylindrical guide 41 where the ring groove 5 of the bolt 4 is provided is fitted. I have.

In a plurality of holes provided in the peripheral wall portion of the cylindrical guide 41,
The ball 42 which is fitted and locked in the ring groove 5 and grips the bolt 4
Are mounted so as not to fall off, and can be moved in the radial direction of the cylindrical guide 41.

A sleeve 43 is mounted on the outer peripheral portion of the cylindrical guide 41 so as to be slidable in the axial direction. The sleeve 43 is formed by a spring 44 interposed between the sleeve 43 and an annular retaining ring. It is constantly pressed and biased to the position where it cannot be removed at 45. Each of the balls 42 projects toward the center of the cylindrical guide 41 by closing the outer peripheral side of the mounting hole with the inner peripheral surface of the sleeve 43, and is fitted and locked in the ring groove 5 to securely hold the bolt 4. Can be grasped.

The lower inner diameter of the sleeve 43 is formed one step larger than the other inner diameter portions.
Each ball 42 can be released to the outer diameter side of the cylindrical guide 41 by being positioned on the outer peripheral side of the cylindrical guide 41. Thus, the grip of the bolt 4 by each ball 42 is released.

An outer flange-shaped stepped portion is integrally provided at an upper end portion of the sleeve 43, and the stepped portion corresponds to a lower end inner flange portion of a cylindrical nut 46 provided integrally with a lower end of the housing 32. In contact with the nut 46, the nut 46 is prevented from coming off.

On the other hand, retainers 47, 4
8, spring 49, bearing 38 and collar 50 are mounted movably in the axial direction, these are wrench shaft
An extension shaft 51 integrally fixed to an upper end portion of the 35 via a not-shown fixing pin is prevented from coming off, and constitutes a rotation torque transmission mechanism.

The extension shaft 51 has a wrench flat and is provided with a window 52. A torque limiting means 53 is attached to the upper end of the extension shaft 51 via a key (not shown).

The torque limiting means 53 is configured to limit the transmission torque only for the operation of tightening the bolt 4, and a rotating handle 54 for rotating the wrench shaft 35 is attached to the torque limiting means 53. The rotary handle 54 is provided with a drive socket 55 for connecting a torque wrench (not shown).

On the other hand, inside the wrench shaft 35, seating detecting means 56 whose lower end projects into the wrench socket 39 is inserted through a bearing 57 so as to be slidable in the axial direction, and the seating detecting means 56 includes a spring 58. , The lower end is immersed in the wrench shaft 35 by fitting the head of the bolt 4 to the wrench socket 39, and the upper end is projected upward from the bearing 57. I have.
By confirming the protrusion from the outside through the window 52, it is possible to confirm that the head of the bolt 4 is securely fitted to the wrench socket 39.

As shown in FIG. 2, the housing 32 is provided with a pin hole 59, and an outer peripheral portion corresponding to the pin hole 59 of the wrench shaft 35, as shown in FIG. 1 and FIG.
A ring groove 60 is provided. And this ring groove 60
The lock pin 61 which constitutes the lock means 62 together with the pin hole 59 is locked.

 Next, the operation of the present embodiment will be described.

When installing the channel fastener 3, use the handle
33 is pulled up to compress the spring 49 and the wrench shaft 35
The housing 32 is moved upward. Then, the sleeve 43 of the gripping means 40 at the lower end of the wrench shaft 35 is pulled up by the nut 46, and the large inner diameter portion of the lower end of the sleeve 43 corresponds to the outer peripheral side of each ball 42, and each ball 42 escapes to the outer diameter side. Is ready to be used. That is, gripping means
40 is open.

After doing this, the wrench socket at the lower end of the handling device 31
At 39, the head of the bolt 4 of the channel fastener 3 is fitted. Then, the seating detecting means 56 slides upward against the urging force of the spring 58, and its upper end projects upward from the bearing 57. The protruding state and the protruding amount can be confirmed from the outside via the window 52, whereby it is possible to confirm whether or not the fitting state is perfect.

After confirming that the bolt 4 is completely fitted,
Release the handle 33. Then, due to the urging force of the spring 49, the housing 32 moves downward with respect to the wrench shaft 35, and the sleeve 43 similarly moves downward to the state shown in FIG. Thereby, each ball 42 is pushed out to the center side, and is fixed in a state where each ball 42 is engaged with the ring groove 5 of the bolt 4. Each ball 42 is prevented from moving toward the outer diameter side unless the sleeve 43 is pulled up, so that the bolt 4 is completely grasped by the grasping means 40.

In this state, if the handle 33 is pulled up, the gripping means 40 is opened, so that the lock pin 61 is locked in the ring groove 60 through the pin hole 59. This allows
The movement of the housing 32 in the axial direction with respect to the wrench shaft 35 is fixed, so that the locking means 62 locks the operation of the gripping means 40 in the gripping state.

Next, the handling device 31 is made vertical, and the channel guide 34 is applied to the corner c of the channel box 2. As a result, the center of the bolt 4 is accurately positioned at the mounting center.

Next, the rotating handle 54 is rotated clockwise by hand, and the bolt 4 is tightened and fixed to a specified torque. At this time, if an excessive tightening torque acts on the rotary handle 54, the torque limiting means 53 operates with a preset limit torque, and excessive tightening of the bolt 4 is prevented.

Since the set torque of the torque limiting means 53 can be adjusted, the set torque should be set within the specified tightening torque of the bolt 4.
It is also possible to prevent excessive torque from acting on the tightening up to the seating. In this case, the tightening up to the specified torque is performed by connecting a torque wrench to the wrench flat of the extension shaft 51.

When the channel fastener 3 is to be removed, the handling device 31 is seated on the bolt 4 of the channel fastener 3 by the same operation as that described above, and after confirming that the seating device 56 is securely seated, the gripping device 40 is used. Grasp the ring groove 5 of the bolt 4. Then, the gripping state is further locked by the locking means 62.

Next, a wrench (not shown) is attached to the wrench flat of the extension shaft 51, and the wrench shaft 35 is loosened and rotated, or the drive socket 55 of the rotating handle 54 is
A torque wrench (not shown) is connected, the wrench shaft 35 is loosened and rotated, the bolt 4 is loosened, and the channel fastener 3 is removed.

As described above, when the bolt 4 is tightened, the torque limiting means 53 operates with the preset limit torque, and the bolt 4 can be securely tightened to the specified torque without being excessively tightened to the specified torque. Damage can be prevented.

In addition, the seating detecting means 56 allows the user to confirm at hand whether the wrench socket 39 is securely fitted to the bolt 4, so that the grasping operation can be performed accurately, and furthermore, the grasping is continuously performed. Since monitoring can be performed, work can be performed safely.

Further, since the operation of the gripping means 40 can be locked by the locking means 62 with the bolt 4 being gripped, there is no problem that the channel fastener 3 is dropped into the spent fuel storage pool, and the skill of the worker is reduced. Work can be performed accurately without being affected.

Further, since the torque limiting means 22 limits the transmission torque only for the tightening operation of the bolt 4, even if the loosening operation requires a torque larger than the tightening torque, it is not necessary to use another handling device, and the work is not performed. Efficiency can be improved.

In the above embodiment, the channel guide 34 is applied to the corner c of the channel box 2 and the handling device 31
Although the description has been given of the positioning of the fuel cell, the guide may be guided inside the handle of the fuel handle 1 or the inside of the channel box 2.

Alternatively, the set torque of the torque limiting means 53 may be the specified tightening torque of the bolt 4, and the management of the tightening torque and the prevention of excessive tightening may be performed at once without using a torque wrench.

Further, various changes can be made, such as using power for rotating the rotary handle 54, and providing a stroke detecting means in addition to the seating detecting means 56.

[Effects of the Invention] As described above, according to the present invention, since the tightening operation of the bolt is performed through the torque limiting means, it is possible to prevent the bolt from being over-tightened and prevent the bolt from being damaged.

Further, since the seat detection means can continuously monitor that the wrench socket has completely fitted the bolt, the gripping operation can be performed accurately, and the reliability of the operation can be improved.

In addition, since the operation of the gripping means is locked by the locking means in a state where the bolt is gripped, there is no problem such as dropping the channel fastener to the spent fuel storage pool, so that accurate work can be performed without skill. it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a channel fastener handling apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a plan view of FIG. 3, and FIG. 5 is a partial sectional view showing a conventional channel fastener handling apparatus. DESCRIPTION OF SYMBOLS 1 ... Fuel handle, 2 ... Channel box, 3 ... Channel fastener, 4 ... Bolt, 5 ... Ring groove, 31 ... Handling device, 32 ... Housing, 34 ... Channel guide, 35 ... Wrench shaft, 38 ... Wrench socket, 40 ... Gripping means, 51
... Extension shaft, 52 ... Window, 53 ... Torque limiting means, 54 ... Rotating handle, 55 ... Drive socket, 56 ... Seat detection means, 62 ... Lock means.

Claims (1)

(57) [Claims] 1. A channel fastener handling device for handling a channel fastener for fixing a channel box to a fuel handle, comprising: a housing having a channel guide for aligning a center of a bolt of the channel fastener with a mounting center thereof; A wrench installed in the housing, the wrench having a wrench socket mounted on the head, a gripping means for gripping the bolt with the wrench socket mounted on the bolt, a torque limiting means for limiting transmission torque, and a rotating handle A shaft, seating detection means which is slidably inserted into the wrench shaft, a lower end portion of which projects into the wrench socket, and is immersed by mounting the wrench socket on a bolt head; and a relative position between the housing and the wrench shaft. By restricting movement, Locking means for locking the operation of the gripping means while the bolt is being gripped, the channel fastener handling apparatus.