JPS5949148B2 - Bolt attachment/detachment transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for automatically attaching, detaching, and transferring bolts, and more particularly to an apparatus suitable for attaching, detaching, and transferring stud bolts attached to a nuclear reactor pressure vessel.

The reactor pressure vessel is constructed such that the pressure vessel body and the upper mirror, which is a sealed head placed on the pressure vessel body, are connected by stud bolts, so that the entire pressure vessel is hermetically sealed.

To confirm the safety of a nuclear reactor, it is necessary to regularly remove the upper mirror of the pressure vessel once a year, but in this case, all of the dozens of bolts attached to the flange of the pressure vessel must be removed.

In the past, bolts were removed manually, but
This bolt has a diameter of 150 mm, a length of 1800 mm, and a weight of about 250 mm, so it takes a lot of effort and time to remove it.

Furthermore, there was a risk that workers would be contaminated by radioactivity around the pressure vessel, making it impossible to work for long periods of time, further deteriorating work efficiency.

For this reason, the inventor previously developed a bolt attachment/detachment transfer device shown in FIG. 1, and greatly improved workability.

To explain the outline of this device, a plurality of female threaded portions (not shown) are formed inside the hanging tool main body 7.
After placing the hanging tool body 7 on multiple bolts (six are shown), insert the hanging tool body 7 through the opening 7a and insert the rotating shaft of the bolt rotation device (not shown) into the square hole 3a of the bolt 3. The bolt is rotated to release the screwed state between the bolt 3 and the pressure vessel 2.

When this screwed state is released, the bolt 3 is removed from the hanging tool main body 7.
The bolt 3 is screwed into a female threaded portion formed inside the main body that rises to the side.

When the screwing state between the bolt 3 and the pressure vessel 2 is completely released, the hanging tool main body 7 is pulled up together with the bolt via the transfer tool 9 and transferred to a predetermined location by an overhead running lane.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bolt attachment/detachment/transfer device that allows good engagement between the bolt and the suspender main body and improves the operability of the device.

In short, the present invention is a device characterized by comprising an upper guide, a main guide that engages with the upper guide to rotate the bolt, and a hanging body disposed within the upper guide and the main guide.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a cross-sectional view of the suspension main body 7, and the left side of the figure shows the state in which the bolt 3 and the pressure vessel are being unscrewed.
The right side shows a state in which the screwed state is released and the bolt 3 can be suspended and transferred.

First, when removing the bolts 3 from the pressure vessel, the guide tube 7b formed at the lower part of the hanging tool main body 7 is placed on each bolt 3, and the hanging tool main body 7 is attached to the bolt to be removed.
position.

13 is an upper guide rotatably supported by a bearing 16, and 14 is a main guide having a bolt retaining portion 14a that engages with the top of the bolt 3 at its lower end.

A keyway 14b is formed in the upper inner wall of the main guide 14 and engages with a key 13a formed in the upper guide 13.

The upper guide 13 and the main guide 14 may be engaged with each other by engaging the key groove and the key, or may be permanently connected by welding.

Reference numeral 15 denotes a female threaded body attached to the suspender main body 7 via a packing 18, and is screwed into a male thread formed on a part or the entire length of the outer peripheral wall of the main guide.

Reference numeral 20 denotes a hanging body disposed within the upper guide 13 and the main guide 14 so that the central axis of these guides coincides with the central axis of itself, and the lower end is a female thread formed at the top of the bolt 3. External thread 20a screwed into the part
is formed.

Next, a method for removing the bolt 3 using this device will be explained.

First, in the state shown in the figure, the rotation shaft 11a of the bolt rotation device 11 is inserted into the keyway 20b of the hanging body 20 by inserting it through the keyhole 13a formed in the upper guide 13,
By rotating the hanging body 20, the male thread 2 at the tip
0a is screwed into the female threaded portion of the bolt 3.

This operation is performed in advance for all the hanging bodies 20 provided on the hanging tool main body 7.

Subsequently, the rotation shaft of the bolt rotation device is replaced with the rotation shaft 11b that engages with the key hole 13a, and the upper guide 13 is rotated.

As a result, the rotational force is transferred to the bolt engaging portion 14a of the main guide 14.
It is transmitted to the bolt 3 through the , and the screwed state of the bolt is released.

As the screwed state is released, the bolt 3 rises and the main guide 14
The male threaded part and the female threaded part 15 are screwed together, and the bolt can be hung.

In this case, if the entire outer wall of the main guide is formed with a male thread, the male thread part and the female thread part 15 are screwed together in advance, and as the bolt 3 rises, the main guide 14 also rises while being threaded with the female thread part 15. I will do it.

Further, if a male threaded portion is formed in a part, the main guide 14 and the upper guide 13 will be raised by the lifting force of the bolt until the male threaded portion and the female threaded portion 15 are screwed together.

In this case, the inner body of the hanging body 20 is rotatably supported by the flange body 21 with respect to each guide 13 and 14, so even if these guides rotate, there is no effect on the threaded state with the bolt 3. I don't accept it.

Once all the bolts 3 and the pressure vessel have been unscrewed using the above method (the state shown on the right side of Figure 2), lift the hanging tool body 7 using a crane or the like and move the bolts to another location. .

In this case, since the hanging body 20 is supported by the flange body 21, there is no fear that the bolt 3 will fall off the guides 13 and 14 even if the bolt 3 is suspended.

Next, the bolts 3 can be easily attached by performing the above-described method in reverse order.

By carrying out this invention, bolts can be automatically and reliably attached and detached, and the working time can be greatly reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the bolt attachment/detachment transfer device, FIG. 2 is a partial cross-sectional view of the suspender main body, and FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. 3... Bolt, 7... Hanging tool body, 13... Upper guide, 14... Main guide, 15... Female threaded body. , 16...Bearing, 20...Hanging body, 20a...
...Male thread.

Claims (1)

[Claims] 1. In a suspension device that attaches, detaches, and transfers bolts, there is an upper guide rotatably supported by a bearing, a main guide connected to this upper guide, and a A hanging device includes a hanging body having a male thread formed at the end thereof to be screwed into the stud hole in the upper part of the bolt, and a female threaded body which is screwed to the male thread formed in at least a part or the entire length of the outer peripheral wall of the main guide. A bolt attachment/detachment transfer device characterized by being provided in the main body.