JPS6329594B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large bolt cleaning device, and more particularly to a bolt cleaning device suitable for cleaning stud bolts that tighten an upper mirror, which is the upper cover of a nuclear reactor pressure vessel.

When performing periodic inspections of the reactor and replacing fuel, the upper mirror must be removed. When the upper mirror is removed, water is filled in the well provided at the top of the pressure vessel to prevent radioactive contamination. will be held. In this case, the stud bolts that attach the upper mirror to the pressure vessel body also become soaked in water, causing rust, and the bolts must be cleaned before and after removing and attaching the nuts.

Figure 1 shows how to clean stud bolts. The stud bolt 3 is inserted through the flange 1a of the upper mirror 1 and is threadedly engaged with the flange 2a of the pressure vessel main body 2, and the nut (not shown) is threadedly engaged with the threaded portion 3a of the bolt 3, which is the threaded portion of the nut. . When cleaning a bolt, first a plastic bag 4 is placed over the threaded portion 3a, and the cleaning is carried out manually using a wire brush with the plastic bag 4 in hand. Wearing plastic bags is intended to prevent the scattering of radioactive dust generated during cleaning work, but the effect of preventing scattering is not necessarily sufficient, and there is a high risk that workers will be exposed to radiation internally if they inhale it. Moreover, it is difficult to collect the dust. Additionally, as more than 100 stud bolts are attached to each pressure vessel, manual cleaning takes a long time and increases the risk of exposure to radiation.

The purpose of this invention is to eliminate the above-mentioned problems and provide a device that automatically cleans bolts. More specifically, it is an object of the present invention to facilitate the movement of the device and to remove brushes when installing the device with bolts. To provide a bolt cleaning device having a handle incorporating a support moving mechanism so as not to get caught.

In short, this invention attaches a handle to the upper part of the device main body, suspends the device from this handle to facilitate movement, and connects the support to the handle so that it can move in a direction perpendicular to the central axis of the bolt.

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

In FIG. 2, a cylindrical cleaning device main body 11 is arranged with respect to the threaded portion 3a of the stud bolt 3 protruding from the flange 1a of the upper mirror so that its center axis is located on the center axis of the threaded portion 3a. There is. Reference numeral 13 denotes a support disposed in an annular space formed between the cleaning device main body 11 and the threaded portion 3a, and a brush 12 is attached to the threaded portion 3a side. A guide 9 is fixed to the upper end of the support 13, and the guide 9 is inserted into the engagement hole 10a of the rotary disk 10. A tuning member 26 is attached to the upper part of the rotary disk 10 to ensure rotation of the rotary disk 10 and move the rotary disk up and down, and the tuning member 26 is further connected to the handle 7 by screws 27. Reference numeral 6 indicates a stopper screwed onto the upper cover 28. On the other hand, a lower guide 1 is provided at the lower end of the support 13.
5 is formed, and the engagement hole 1 formed in the rolling wheel 14
By connecting with 4a, the support 13 becomes the rolling wheel 1.
4, it is rotatably supported.

When attaching the bolt cleaning device configured as described above to a bolt, the operator can hang and carry the entire device by holding the handle 7.
In addition to this, it also has the function of moving the support 13 as described below. This will be explained in detail below.

First, by suspending the main body of the cleaning device by the handle 7, the handle 7 is attached to the stopper 6 as shown in the left half of FIG.
is pulled up to the top 6a. As a result, the rotary disk 10 that engages with the handle 7 also rises in the X' direction.
Reference numeral 8 denotes a sliding plate attached to the guide 9, the end of which is in contact with a slope 10b formed on the side wall of the rotary disk 10. As the rotary disk 10 rises, the sliding plate 8 relatively slides down this slope due to the weight of the guide 13, and the engagement between the guide 9 and the engagement hole 10a of the rotary disk 10 is released. With this relative lowering of the sliding plate 8, the entire support 13 rises in the X' direction, and at the same time the engagement between the guide 9 and the engagement hole 10a is released, and at the same time the engagement between the lower guide 15 and the roller 14 is released. is also released, and the support 13 moves in the X direction. As a result, a gap is formed between the brush 12 and the threaded portion 3a, or a slight contact is made between the brush 12 and the threaded portion 3a, thereby facilitating attachment of the device to the bolt.

Next, when the bolt cleaning device is attached to the threaded portion 3a, the handle 7 and the rotary disk 10 are moved by their own weight.
Descend in the Y′ direction. Engagement hole contact portion of guide 9;
Since the rolling wheel contact surface of the lower guide 15 is formed in a substantially conical shape, as the rotary disk 10 descends, the upper and lower guides 9 and 15 gradually open into the engaging hole 10a and the engaging hole 14a of the rolling wheel 14. and support 1
3 in the Y direction, and finally engage completely as shown in the right half of FIG.

Once the bolt cleaning device has been installed as described above, the rotating shaft of the motor (not shown) is inserted into the engagement groove 21 formed in the upper part of the cleaning device main body. As a result, the rotational force of the motor is transmitted to the support 13 via the rotary disk 10 and the guide 9.
Rust, dust, etc. on the threaded portion 3a are removed by a brush provided on the threaded portion 3a.

Since the present invention is equipped with the above-mentioned handle, it is easy to carry the device, and when the device is attached or detached, it can be moved to the inner wall side of the brush body, making it easy to attach or detach the device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a stud bolt insertion portion of a nuclear reactor pressure vessel, and FIG. 2 is a sectional view of a bolt cleaning device according to the present invention. 3... Stud bolt, 6... Stopper, 7...
...Handle, 10... Turntable, 13... Support, 2
6... Tuning member.

Claims (1)

[Claims] 1 A handle is attached to a tuning member that rotatably supports the rotary disk, and the handle is configured to be movable up and down within a certain range by a stopper attached to the top cover, and the handle is moved in the same direction as the moving direction of the handle via the tuning member. 1. A bolt cleaning device having a handle, characterized in that the support is configured to be movable in a direction perpendicular to the axis of the bolt by means of a rotary disk that moves.