JPS6351748B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for large bolts, and in particular to a bolt cleaning device for cleaning stud bolts that tighten an upper mirror, which is the upper cover of a nuclear reactor pressure vessel, and for replacing brushes used for cleaning the bolts. Regarding cleaning equipment.

During periodic inspections of the reactor and fuel replacement, the upper mirror must be removed. Water filling is done. 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 a method for cleaning 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 the bolt, first, a plastic bag 4 is placed over the threaded portion 3a, and the cleaning is performed manually by placing the hand in the plastic bag 4 and using a wire brush. 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 a single pressure vessel, manual cleaning takes a long time and increases the risk of exposure to radiation.

A device for cleaning large stud bolts was devised in Utility Model Application No. 58283/1983. In the device according to this invention, the wire brush is rotated in contact with the bolt screw as in the present application, but there are the following problems.

(1) The wire brush is always pressed against the stud using a coil spring 48 shown in FIG.

This forces the device to be pushed into the stud in opposing contact with the stud, which can cause cracking and damage to the stud in large studs made of special materials that are sensitive to scratches.

(2) Air is taken in from the middle of the outer cylinder of the device, and air is extracted from the middle of the outer cylinder of the device. In addition, the inner cylinder is provided with a plurality of air intake ports 3c, and the resistance to air flow is large. Dust collects at the bottom of the device.

(3) The brush 4 has approximately the same length as the outer cylinder 2. To replace the brush, remove bolts 11 and 12.
It is necessary to take out a heavy device including a rotating body from the outer cylinder, and it takes time and effort to replace the brushes.

The purpose of the present invention is to eliminate the above problems and provide a device that automatically cleans bolts. More specifically, the purpose of the present invention is to provide a device that automatically cleans bolts. More specifically, the bolt cleaning brush is configured to be replaceable, and worn brushes can be replaced. The pressure of the brush against the stud bolt can be kept constant.
To provide a bolt cleaning device in which the rigidity of a brush can be changed by replacing the brush depending on the purpose.

In short, the present invention is configured such that a support to which a brush is attached and members such as a guide for transmitting the rotational force of a motor are detachably attached to the support, so that the brush can be removed from the main body of the device along with the support.

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

Fig. 2 shows the bolt cleaning device attached to the stud bolt 3, and the cylindrical cleaning device main body 11 is attached to the threaded portion 3a of the stud bolt 3 protruding from the flange 1a of the upper mirror. It is arranged so as to be located on the central axis of the portion 3a. A plurality of supports 13 are arranged 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. The upper end of this support 13 is fixed to a mounting piece 23 with a screw 22, and the mounting piece 2
3 is connected to the guide 9 by welding. Further, a lower guide 15 is attached to the lower end of the support 13, and this lower guide 15 is connected to the engagement hole 14 of the wheel 14.
It is fitted into and engaged with a.

Next, the brush 12 provided on the support 13 comes into contact with the threads and valleys of the threaded portion 3a and slides on the surface of the threaded portion 3a to peel off and remove rust. For this reason, the brush 12 needs to be relatively rigid, such as a wire brush. However, if a highly rigid brush is used, the brush will get caught on the threaded part of the bolt, making it difficult to install. When the support 13 is installed in a computer, each support 13 has a structure that expands in the X direction in the figure. To explain the operating state of this support 13 in detail, when attaching the cleaning device main body 11 to the stud bolt, the device main body is suspended by the handle 7 provided at the top of the device main body and inserted into the threaded part 3a. However, by suspending the main body of the device, the handle 7 is pulled upward as shown in the left half of FIG.
As a result, the guide 9 comes off from the engagement hole 10a due to the weight of the support 13, the sliding plate 8 attached to the upper part slides down the slope part 10b of the rotary disk 10, and each support 13 moves in the X direction. When the installation of the device main body 11 is completed, the handle 7 and the rotary disk 10 that engages with it are lowered, the guide 9 is refitted into the engagement hole 10a, and each support 13 is
The brush 12 strongly contacts the threaded portion 3a. Note that reference numeral 6 is a stopper that holds the handle 7 from being pulled up to a certain limit.

The bolt cleaning device is attached to the stud bolt in the manner described above, and then the rotating shaft of the motor (not shown) is inserted into the engagement groove 21 formed at the upper end of the device. As a result, the support 13 is rotated by the rotational force of the motor, and the brush 12 removes rust, dust, etc. from the threaded portion 3a.

Next, if the bolt is cleaned for a long time, the brush 12 will become damaged, but in this case, the brush can be replaced by the following method. First, the screw 24 connecting the skirt portion 11b, which forms a part of the cleaning device body, and the upper cylindrical portion 11a is removed. Next, the handle 7 and the tuning member 26
Remove the screw 27 that connects the This tuning member 26 rotatably supports the rotary disk 10 and is connected to the handle 7 by screws 27 to move the rotary disk 10 up and down in response to the vertical movement of the handle 7. Therefore, by removing the screws 27, the engagement relationship between the handle 7 and the rotary disk 10 is eliminated. Once the screws 27 have been removed, pull up the handle 7 and remove the top cover 2 which is screwed into the stopper 6 via the stopper 6.
8 and the cylindrical portion 11a connected to the upper lid 28 by screws 29 are removed as one piece from the skirt portion 11b. This will expose the support 13, so remove the screw 22 and attach the support 13 to the mounting piece 2.
Remove from 3. Then, the brush 12 is pulled out from the rear wheel 14 and the support 13 and the brush 12 are replaced.

By implementing this invention, the brush can be freely replaced, so bolts can be cleaned with a new brush at all times, and the rigidity of the brush can also be freely selected depending on the purpose.

[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, 9... Guide, 11a... Cylindrical part, 11b... Skirt part, 12... Brush, 13... Support, 22,
24, 27...screws, 23...mounting pieces, 28...upper lid.

Claims (1)

[Claims] 1 The lower end of the cylindrical device body has a dust suction passage, the lower end is located in the engagement hole of the rolling wheel provided at the bottom of the device body, and the engagement hole of the rotary disk through which the guide connected to the upper end is rotationally driven. In an apparatus for cleaning a large stud, which is provided with a plurality of supports with brushes inserted therethrough, and in which the supports are displaced toward a wall inside the apparatus main body when the apparatus is suspended by a handle, the apparatus main body is connected to a skirt portion 11b. The cylindrical part 11a is connected with a screw 24, the upper end of the cylindrical part 11a and the upper cover 28 are connected with a screw 29, and the upper end of the brush is connected with a mounting piece 23, which fixes the guide 9 to the guide, with a screw 22. , a brush removal type bolt cleaning device characterized in that it is formed into an assembly type device.